JP4538977B2 - Inorganic organic composite material manufacturing method, actuator manufacturing method, and artificial muscle manufacturing method - Google Patents

Description

【化２】

【化３】

に示すシッフ塩基系、
【化４】

【化５】

【化６】

【化７】

【化８】

【化９】

【化１０】

【化１１】

【化１２】

に示す安息香酸エステル系、
【化１３】

【化１４】

に示すビフェニル系、
【化１５】

に示すターフェニル系、
【化１６】

【化１７】

【化１８】

【化１９】

に示すシクロヘキシルカルボン酸エステル系、
【化２０】

【化２１】

【化２２】

に示すフェニルシクロヘキサン系、
【化２３】

に示すビフェニルシクロヘキサン系、
【化２４】

に示すシクロヘキシルシクロヘキサン系、
【化２５】

に示すビフェニルシクロヘキサン系、
【化２６】

【化２７】

に示すシクロヘキシルシクロヘキサンエステル系、
【化２８】

に示すビフェニルシクロヘキサン系、
【化２９】

【化３０】

に示すピリミジン系、
【化３１】

【化３２】

に示すジオキサン系、
【化３３】

【化３４】

【化３５】

に示すシクロヘキシルカルボン酸エステル系、
【化３６】

【化３７】

【化３８】

【化３９】

に示すシクロヘキシルエタン系、
【化４０】

【化４１】

に示すアゾキシ系、
【化４２】

に示すアゾ系、
【化４３】

【化４４】

に示すコレステロール系などがある。さらに、不斉炭素を有した強誘電性あるいは反強誘電性を示す液晶分子、主鎖あるいは側鎖にメゾゲン基を有する高分子液晶、有機金属錯体を用いた液晶分子なども利用可能である。なお、液晶は一種類のものを単独で用いても良く、二種類以上のものを混合して用いても良い。
【００２８】
この発明において、ホスト無機層状物質の層間に存在するゲスト有機物質が、液晶性を有する有機分子からなる少なくとも一層の有機分子層である無機有機複合材料は、この少なくとも一層の有機分子層をホスト無機層状物質の層間に直接インターカレートすることにより製造することができる。例えば、ホスト無機層状物質がＨＴｉＮｂＯ₅ である場合を考えると、このＨＴｉＮｂＯ₅ は固体酸の性質を有するので、塩基性有機分子、特にアミン系分子がインターカレーションを容易に行うことができるものであり、これは一般的に知られた事実である。従って、アミン系液晶であれば、ＨＴｉＮｂＯ₅ の層間に一段階のインターカレーションで直接挿入可能と考えられる。このアミン系液晶の分子の例を挙げると、下記のとおりである。これらは非対称な三級アミンをベンゼン環あるいはシクロヘキサン環と結合させた化合物である。
【００２９】
【化４５】

【化４６】

【化４７】

【化４８】

【化４９】

【化５０】

【００３０】
これらのアミン系液晶をＨＴｉＮｂＯ₅ 結晶の層間に直接インターカレートする方法としては、具体的には、例えば、
（１）アミン系液晶を加熱して等方性液体とし、その中にＨＴｉＮｂＯ₅ 結晶を入れる方法
（２）アミン系液晶を溶媒（例えば、水、エタノール、あるいはこれらの混合溶媒など）に溶かし、その中にＨＴｉＮｂＯ₅ 結晶を入れる方法
を用いることができる。
以上のように、アミン系液晶とそれに適した挿入方法を選択すれば、二段階法を用いずに無機層間に直接液晶分子を挿入することができる。
【００３１】
しかしながら、無機層状物質の層間に液晶分子を直接挿入するのが容易ではない場合がある。その場合には、二段階以上のインターカレーションを行う。例えば、まず第一段階目のインターカレーションでは、無機層状物質にインターカレーションが容易であり、かつ液晶と親和性がある有機分子を挿入する。このプロセスを経たインターカレーション化合物は、第二段階目のインターカレーションプロセスで液晶分子を挿入することが可能となる。例えば、無機層状物質としてＨＴｉＮｂＯ₅ （ＫＴｉＮｂＯ₅ を塩酸処理することにより得られる）を用いた場合には、アミノ基を有した有機物（例えば、ｎ−ブチルアミンなど）が第一段階目のインターカレーションで容易に挿入される。そして、このアミノ基を有した有機物が、例えばシアノビフェニル系液晶と親和性が良い場合には、第二段階目のインターカレーションで、この液晶を層間に挿入することが可能となる。
【００３２】
すなわち、ホスト無機層状物質の層間に液晶性を有する有機分子を直接インターカレートすることが困難な場合には、インターカレーションを二段階以上行うことにより無機有機複合材料を製造する。具体的には、ホスト無機層状物質の層間に存在するゲスト有機物質が、層に平行に配置された、液晶性を有する有機分子からなる少なくとも一層の有機分子層を含む複数の有機分子層である無機有機複合材料の製造方法は、複数の有機分子層のうちの液晶性を有する有機分子からなる少なくとも一層の有機分子層以外の有機分子層をホスト無機層状物質の層間にインターカレートする工程と、複数の有機分子層のうちの液晶性を有する有機分子からなる少なくとも一層の有機分子層をホスト無機層状物質の層間にインターカレートする工程とを有する。このうち特に、複数の有機分子層が第１の有機分子層、この第１の有機分子層と異なる第２の有機分子層および第１の有機分子層と同一の第３の有機分子層からなる無機有機複合材料の製造方法は、第１の有機分子層および第３の有機分子層をホスト無機層状物質の層間にインターカレートする工程と、第２の有機分子層をホスト無機層状物質の層間にインターカレートする工程とを有する。
【００３３】
また、複数の有機分子層が、液晶性を有する有機分子からなる少なくとも一層の有機分子層とこの有機分子層を挟む、液晶性を示す有機分子に対して親和性を有する有機分子からなる一対の有機分子層とを含む無機有機複合材料の製造方法は、液晶性を有する有機分子に対して親和性を有する有機分子からなる一対の有機分子層をホスト無機層状物質の層間にインターカレートする工程と、液晶性を有する有機分子からなる少なくとも一層の有機分子層をホスト無機層状物質の層間にインターカレートする工程とを有する。このうち特に、複数の有機分子層が第１の有機分子層、この第１の有機分子層と異なる第２の有機分子層および第１の有機分子層と同一の第３の有機分子層からなり、第２の有機分子層が液晶性を有する有機分子からなり、第１の有機分子層および第３の有機分子層が液晶性を有する有機分子に対して親和性を有する有機分子からなる無機有機複合材料の製造方法は、第１の有機分子層および第３の有機分子層をホスト無機層状物質の層間にインターカレートする工程と、第２の有機分子層をホスト無機層状物質の層間にインターカレートする工程とを有する。
【００３４】
ここで、第一段階のインターカレーションで挿入する、液晶性を有する有機分子に対して親和性を有する有機分子の働きについて説明する。一般に、同じような官能基（例えば、アミノ基、アルキル基、アリル基、スルホン基、シアノ基、カルボニル基など）を有する化合物は良く似た性質を示し、さらにその構造が類似すればするほど、その性質が似る傾向が強い。その結果として、同じような官能基や構造を有する化合物の液体あるいは液晶同士を接触させた場合には、それらの間で容易に混合が生じる。このような状態を、それら化合物間の親和性が高い（良い）という。例えば、シアノビフェニル系液晶に対しては、シアノビフェニル基を有する有機分子群の親和性が高いと考えられる。さらに、シアノビフェニルではなくシアノ基だけであっても比較的親和性が高いと考えられる。以上より、液晶分子を無機層間にインターカレートするためには、第一段階目に以下の特徴を有する有機分子を挿入し、第二段回目以降に液晶分子を挿入すれば良いと考えられる。
（１）第二段階目以降に挿入する液晶分子と同じ官能基を有する
（２）第二段階目以降に挿入する液晶分子と構造が類似している
【００３５】
無機有機複合材料を製造する場合、典型的には、ホスト無機層状物質を所定の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間にゲスト有機物質をインターカレートし、必要に応じて、この工程を使用する有機物質の種類を変えて複数回行う。より具体的には、ホスト無機層状物質の層間に存在するゲスト有機物質が、層に平行に配置された、液晶性を有する有機分子からなる少なくとも一層の有機分子層を含む複数の有機分子層である無機有機複合材料の製造方法は、ホスト無機層状物質を第１の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間に複数の有機分子層のうちの液晶性を有する有機分子からなる少なくとも一層の有機分子層以外の有機分子層をインターカレートする工程と、ホスト無機層状物質を第２の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間に複数の有機分子層のうちの液晶性を有する有機分子からなる少なくとも一層の有機分子層をインターカレートする工程とを有する。このうち特に、複数の有機分子層が第１の有機分子層、この第１の有機分子層と異なる第２の有機分子層および第１の有機分子層と同一の第３の有機分子層からなる無機有機複合材料の製造方法は、ホスト無機層状物質を第１の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間に第１の有機分子層および第３の有機分子層をインターカレートする工程と、ホスト無機層状物質を第２の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間に第２の有機分子層をインターカレートする工程とを有する。
【００３６】
また、複数の有機分子層が、液晶性を有する有機分子からなる少なくとも一層の有機分子層とこの有機分子層を挟む、液晶性を示す有機分子に対して親和性を有する有機分子からなる一対の有機分子層とを含む無機有機複合材料の製造方法は、ホスト無機層状物質を第１の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間に液晶性を有する有機分子に対して親和性を有する有機分子からなる一対の有機分子層をインターカレートする工程と、ホスト無機層状物質を第２の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間に液晶性を有する有機分子からなる少なくとも一層の有機分子層をインターカレートする工程とを有する。このうち特に、複数の有機分子層が第１の有機分子層、この第１の有機分子層と異なる第２の有機分子層および第１の有機分子層と同一の第３の有機分子層からなり、第２の有機分子層が液晶性を有する有機分子からなり、第１の有機分子層および第３の有機分子層が液晶性を有する有機分子に対して親和性を有する有機分子からなる無機有機複合材料の製造方法は、ホスト無機層状物質を第１の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間に第１の有機分子層および第３の有機分子層をインターカレートする工程と、ホスト無機層状物質を第２の有機物質の溶液または融液と接触させて所定の温度で所定の時間保持することによりこのホスト無機層状物質の層間に第２の有機分子層をインターカレートする工程とを有する。
【００３７】
この場合、ホスト無機層状物質を有機物質の溶液または融液と接触させる時間を変化させることによりこのホスト無機層状物質の層間への有機物質の挿入量および層間隔を制御することができる。
【００３８】
特に、第１の有機物質および第２の有機物質を用いて二段階のインターカレーションを行う場合、これらの第１の有機物質および第２の有機物質は互いに同一または互いに構造が類似する官能基を有する。これらの官能基は、例えば、アミノ基、アルキル基、アニル基、スルホン基、シアノ基およびカルボニル基からなる群より選ばれた少なくとも一つの官能基である。
【００３９】
この発明において、ホスト無機層状物質の層間へのインターカレーションを行う場合、一般にその反応時間は、好適には、１時間以上、１カ月間以下とする。これは、反応時間が１時間より短いとインターカレーション反応が十分でなく、層間隔が一定にならないという不都合が起こりやすいからであり、一方、インターカレーション反応が平衡に達し、層間隔が一定になるのは、１カ月もあればよいからである。反応時間は、さらに好適には１２時間〜３日とする。この程度の反応時間で十分にインターカレーションできる場合が多い。
【００４０】
また、インターカレーションの際の温度については、好適には、例えば０℃以上２００℃以下とする。下限温度については、温度が０℃より低いと、水溶液を用いている場合には水分の凝固という不都合が起こるからである。同様に、水溶液ではなく、有機物質のみからなる液体を用いているという場合には、有機物質の凝固点以下では不都合が生じる。上限温度については、温度が２００℃より高いと、有機分子の熱分解、蒸発などの好ましくない反応が起こるためである。より好適には、温度を室温（２０℃）以上、１５０℃以下とする。これは、温度が室温（２０℃）より低いと、インターカレーション反応が速やかに進まない（遅い）という不都合が起こる一方、温度が１５０℃より高いと有機分子の熱分解や気化などの好ましくない反応が生じる可能性が高くなるためである。
【００４１】
さらに、無機有機複合材料の組成については、好適には、ホスト無機層状物質（例えば、ＨＴｉＮｂＯ₅ ）１モルにつき、ゲスト有機物質の総量を０．０１モル以上１００モル以下とする。これは、ゲスト有機物質の総量が０．０１モルよりも小さいと、有機分子層による発生力が小さくなり、駆動が難しくなるという不都合が起こる一方、１００モルより大きいと無機層状物質の層間隔が拡大しすぎて形状が保てないという不都合が起こるためである。このホスト無機層状物質に対するゲスト有機物質の総量は、より好適には０．１モル以上１０モル以下とする。
【００４２】
この発明の第３の発明によるアクチュエータにおいては、上記のような無機有機複合材料の面に対して垂直方向に電場を印加することにより無機有機複合材料のホスト無機層状物質の層間隔を変化させることにより駆動を行う。このアクチュエータは、ホスト無機層状物質の面に垂直な方向に電場を印加するための電極を有し、典型的には、ホスト無機層状物質の一方の面および他方の面にそれぞれ電極が設けられている。このアクチュエータは一つの要素部（モジュールあるいはユニット）により構成されることも、所望の大きさにするための複数の要素部の組み合わせにより構成されることもある。
【００４３】
アクチュエータの形状は基本的にはどのような形状であってもよく、使用目的などに応じて設計される。具体的には、アクチュエータは、無機有機複合材料の伸縮方向を軸とする柱状（円柱状、角柱状など）または繊維状の形状を有し、好適には、電場印加によるホスト無機層状物質の層間隔変化時にその形状を保ち、あるいは液晶の漏洩を防ぐために、少なくともその側面の一部に伸縮性の物質がコーティングされるが、コーティングを省略してもよい。アクチュエータは、典型的には、無機有機複合材料の伸縮方向を軸とする柱状または繊維状の形状を有する要素部が複数直列接続されたものからなるものであり、あるいはこの柱状または繊維状の形状を有する要素部が複数直列接続されたものが複数並列接続された（あるいは束ねられた）構造を有する。伸縮運動に支障を生じないようにするために、これらの要素部相互間は接着などにより一体的に結合される。
【００４４】
アクチュエータは、無機有機複合材料の伸縮方向が主面に垂直な膜状または板状の形状を有することもあり、好適には、電場印加によるホスト無機層状物質の層間隔変化時にその形状を保ち、あるいは液晶の漏洩を防ぐために、少なくともその表面の一部に伸縮性の物質がコーティングされるが、コーティングを省略してもよい。アクチュエータは、典型的には、膜状または板状の形状をする要素部が複数直列接続されたものからなるものであり、あるいはこの膜状または板状の形状を有する要素部が複数直列接続されたものが複数並列接続された（あるいは束ねられた）構造を有する。伸縮運動に支障を生じないようにするために、これらの要素部相互間は接着などにより一体的に結合される。
アクチュエータはさらに、上記のような種々の形状のものを使用目的などに応じて適宜に組み合わせることにより構成してもよい。
【００４５】
この発明による人工筋肉においては、無機有機複合材料の面に対して垂直方向に電場を印加することにより無機有機複合材料のホスト無機層状物質の層間隔を変化させることにより駆動を行う。その他のことは、この発明によるアクチュエータと同様である。この人工筋肉は、例えば拮抗筋の構成に適用することができる。この場合、人工筋肉は第１の人工筋肉および第２の人工筋肉からなり、第１の人工筋肉および第２の人工筋肉が支柱を共有して拮抗した伸縮動作を行うように構成される。
【００４６】
この発明による無機有機複合材料、アクチュエータまたは人工筋肉は、無機層状物質の層間に存在する液晶性を有する有機分子を外部電場により駆動させ、一方向、すなわち層に垂直方向の伸縮変位を可能とするものである。より具体的には、電場によって無機層状物質の層間に存在する液晶性を有する有機分子の無機層に対する角度を変化させ、それに伴う層間隔の変化をマクロ変位として取り出し、駆動するものである。このような無機有機複合材料が電場印加により駆動される際には、ナノメートルレベルの層間隔の変化が結晶の厚み方向（ｃ軸方向）のみに反映されるので、伸縮の自由度は一方向にしかなく、エネルギー効率が高くなるという利点を有する。
【００４７】
さらに、この無機有機複合材料は層間に存在する液晶性を有する有機分子のために柔軟な構造を有している。従来の無機物を用いた電歪アクチュエータは、伸縮する部位がセラミックスでできているため、柔軟性はほとんどなく、しかも変位は小さい。従って、無機層状物質をマトリックスとしながら、柔軟な性質をも有していることは、この発明によるアクチュエータの大きな利点である。
【００４８】
このようにこの発明によるアクチュエータは、従来のアクチュエータを凌ぐ特性を有するものである。特に、従来の液晶アクチュエータとの比較においては、無機物を骨格としているので強度耐久性に優れ、また層状構造を有するので、その異方性を利用することにより応答速度やエネルギー変換効率が向上する。さらに、従来の無機アクチュエータとの比較においては、柔軟性を有しており、かつ大きな変位が得られるという特徴を有する。
【００４９】
この発明による無機有機複合材料の駆動メカニズムを図１を参照してより詳細に説明する。図１は層状無機物質の層状無機骨格の層間に液晶を保持したこの発明による無機有機複合材料（インターカレーション化合物）の、電圧を印加する前後における構造を示す模式図である。
【００５０】
無機層状物質に有機物のインターカレーションを行うと、一般的に有機分子は無機層に対してある角度で配向した状態で層間に存在している。これが電圧を印加していない状態で図１Ａに相当する。液晶分子が層間にインターカレートされている場合、電圧印加により液晶層は協同的に分子の向きを電場に対して揃えようとする。液晶分子の誘電率異方性が正の場合には、図１Ｂに示すように、液晶分子は長軸方向が電場の向きと平行になるように配向し、このとき層間隔は増大する。一方、液晶分子の誘電率異方性が負の場合には、図１Ｃに示すように、液晶分子は長軸方向が電場の向きと垂直に近づくように配向し、このとき層間隔は縮小する。
【００５１】
この層間隔の変化はナノメートルレベルの微小なものであるが、この変位はもとの層間隔の数〜数十％にも達し、無機有機複合材料の結晶全体を観察すると、そのｃ軸方向（厚み方向）に巨大な変位が生じることになる。無機物を用いたアクチュエータとしては、すでに述べたようにＰＺＴなどの電歪素子があるが、その変位量は０．１％程度であり、この発明による無機有機複合材料を用いたアクチュエータではそれを遥かに上回る変位が得られる。
【００５２】
【発明の実施の形態】
以下、この発明の実施形態について図面を参照しながら説明する。なお、実施形態の全図において、同一または対応する部分には同一の符号を付す。
【００５３】
まず、この発明の第１の実施形態について説明する。この第１の実施形態においては、無機層状物質としてのＫＴｉＮｂＯ₅ の層間に液晶をインターカレートした無機有機複合材料およびその製造方法ならびにこの無機有機複合材料への電圧印加時の変位について説明する。
【００５４】
図２に、電圧無印加時におけるこの無機有機複合材料の構造を示す。図２に示すように、この無機有機複合材料は、無機層状物質としてのＫＴｉＮｂＯ₅ の無機層１１、１２間に、有機分子層としてのブチルアミン層１３、１４を介して、液晶性を示す分子層としての５ＣＢ層１５、１６が挿入された構造を有する。ここで、ブチルアミン層１３、１４および５ＣＢ層１５、１６は、無機層１１、１２間の空間の二等分面に関して鏡像の関係にある分子配向性を有している。ブチルアミン層１３、１４はそのＮＨ₃ ⁺ 側がそれぞれ無機層１２、１３に結合している。そして、５ＣＢ層１５、１６はそれらのＣＮ基が互いに向き合うように配向している。
【００５５】
次に、この無機有機複合材料の製造方法について説明する。
この無機有機複合材料は、ＫＴｉＮｂＯ₅ 単結晶の作製、このＫＴｉＮｂＯ₅ 単結晶の処理によるＨＴｉＮｂＯ₅ 単結晶の作製およびこのＨＴｉＮｂＯ₅ 単結晶に対する二段階のインターカレーションの工程を経て製造される。以下これらの工程について詳細に説明する。
【００５６】
ＫＴｉＮｂＯ ₅ 単結晶の作製
まず、ＫＴｉＮｂＯ₅ 粉末を白金るつぼに入れ、この白金るつぼを大気中において１４００℃で５時間保持した後、１１５０℃まで１０℃／ｈの冷却速度で徐冷し、さらに室温まで冷却して成型体を得る。次に、この成型体の焼成を行う。焼成方法としては、成型体を容積が２０ｍｌの白金るつぼに入れ、さらにこの白金るつぼを一回り大きいアルミナるつぼに入れて、アルミナ製の蓋で密閉する二重るつぼの方法を採用した。この焼成により得られた溶融凝固体を白金るつぼから取り出し、きれいな透明性の単結晶片を選び出した。ＫＴｉＮｂＯ₅ 結晶の形状は、結晶構造の異方性を反映して板状となっているものが一般的であり、機械的操作により単結晶を取り出すと最大（２〜３）ｍｍ×（２〜３）ｍｍ×（１〜２）ｍｍ程度の大きさのものが得られる。ＫＴｉＮｂＯ₅ の結晶構造を図３に示す。
【００５７】
このＫＴｉＮｂＯ₅ 単結晶のＸ線回折パターンを図４に示す。図４より、（００１）の回折ピークのみが見られ、試料測定面がｃ面となっていることがわかる。同図の（００２）回折ピークから計算される面間隔は０．９００ｎｍ（９．００Å）であった。ＥＤＸによりこのＫＴｉＮｂＯ₅ 単結晶の組成の定量分析をしたところ、金属組成比はＫ：Ｔｉ：Ｎｂ＝０．９７：１：０．９８であった。
【００５８】
ＨＴｉＮｂＯ ₅ 単結晶の作製（ＫＴｉＮｂＯ ₅ →ＨＴｉＮｂＯ ₅ ）
上述のようにして得られたＫＴｉＮｂＯ₅ 単結晶を、室温で１規定のＨＣｌ中に入れ、２週間静置した。この処理によりＫＴｉＮｂＯ₅ 単結晶中のＫイオンがＨイオンに交換され、ＨＴｉＮｂＯ₅ 単結晶が得られた。結晶の形状は、イオン交換前のＫＴｉＮｂＯ₅ と殆ど変化はない。ＨＴｉＮｂＯ₅ の結晶構造を図５に示す。
【００５９】
このＨＴｉＮｂＯ₅ 単結晶のＸ線回折パターンを図６に示す。同図の（００２）回折ピークから計算した面間隔はｄ＝０．８４８ｎｍ（８．４８Å）であり、ＫＴｉＮｂＯ₅ より少し小さい値となっている。ＥＤＸによるこのＨＴｉＮｂＯ₅ 単結晶の組成の定量分析をした結果、金属組成比はＫ：Ｔｉ：Ｎｂ＝０．０３：１：０．９８であり、Ｋ成分がほとんど脱離していることがわかった。従って、このＨＴｉＮｂＯ₅ 単結晶は、ＫＴｉＮｂＯ₅ の結晶構造をほぼ保ったまま、Ｋ→Ｈイオン交換が起こってできたＨＴｉＮｂＯ₅ 単結晶であると考えられる。
【００６０】
第一段階インターカレーション：ブチルアミン−ＨＴｉＮｂＯ ₅ 単結晶の作製
上述のようにして得られたＨＴｉＮｂＯ₅ 単結晶へｎ−ブチルアミン（n-Butylamine）のインターカレーションを行う。このインターカレーションは、溶媒に純水を用いて１ｍｏｌ／ｌのアミン溶液を作製し、ＨＴｉＮｂＯ₅ に対してアミンのモル比が大幅に過剰になるようにして、室温にて３日間反応させることにより行った。この操作によって、ｎ−ブチルアミンがＨＴｉＮｂＯ₅ の層間に挿入されたインターカレーション化合物（以下「ブチルアミン−ＨＴｉＮｂＯ₅ 」と呼ぶ）の結晶が得られた。このブチルアミン−ＨＴｉＮｂＯ₅ 単結晶のＸ線回折パターンを図７に示す。図７より、（００１）に由来する回折ピークのみが見られ、（００２）回折ピークから計算される面間隔はｄ＝１．８２１ｎｍ（１８．２１Å）であった。このブチルアミン−ＨＴｉＮｂＯ₅ 結晶の面間隔はＨＴｉＮｂＯ₅ のそれに比較して約０．９７３ｎｍ（９．７３Å）拡大しており、これはブチルアミンが層間に挿入されたことを示している。無機層間に存在するブチルアミンの傾斜角度を図８を参照して見積もると、ＨＴｉＮｂＯ₅ 結晶の層間隔ｄ₁ ＝０．８４８ｎｍ（８．４８Å）、ブチルアミン−ＨＴｉＮｂＯ₅ 結晶の層間隔ｄ＝１．８２１ｎｍ（１８．２１Å）、ｎ−ブチルアミンの分子長ａ＝０．６１６ｎｍ（６．１６Å）、Δｄ＝ｄ−ｄ₁ ＝０．９７３ｎｍ（９．７３Å）であるから、傾斜角度θ＝ａｒｃｓｉｎ（Δｄ／２ａ）＝ａｒｃｓｉｎ（０．９７３／２×０．６１６）＝５２°と見積もられる。
【００６１】
次に、このブチルアミン−ＨＴｉＮｂＯ₅ 単結晶の組成を明らかにするために、酸素循環ＴＣＤ法による窒素の定量分析を行った。ブチルアミン１分子中には窒素原子が１個存在するので、窒素の定量分析を行うことにより、有機分子を含めたインターカレーション化合物の組成を決定することができる。測定結果より得られた組成式は
（ブチルアミン） _0.56 ＨＴｉＮｂＯ₅
であった。
【００６２】
第二段階インターカレーション：５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ ₅ 単結晶の作製
上述のようにして第一段階インターカレーションを行うことにより得られたブチルアミン−ＨＴｉＮｂＯ₅ 単結晶に第二段階インターカレーションを行う。挿入物質は室温ネマティック液晶５ＣＢ（4-aminobutoxy cyanobiphenyl ：Ｃ₅ Ｈ₁₁（Ｃ₆ Ｈ₄ ）₂ ＣＮ）であり、この物質は２２℃〜３５℃の範囲でネマティック相となるものである。まず、ブチルアミン−ＨＴｉＮｂＯ₅ 単結晶数個をガラス製サンプル管の中に入れ、このサンプル管の中にそれらを浸すのに十分な量の５ＣＢ（メルク社製、型番Ｋ−１５）を注いだ。その後、密閉したサンプル管をオーブンに入れ、１３０℃で１２時間〜６０時間の熱処理を行った。
【００６３】
ブチルアミン−ＨＴｉＮｂＯ₅ 単結晶を５ＣＢとともに、１３０℃で２４時間熱処理した試料（以下「５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ₅ 」と呼ぶ）のＸ線回折パターンを図９に示す。図９より、（００１）に由来する回折ピークのみが見られ、（００２）回折ピークから計算される層間隔はｄ＝３．９９４ｎｍ（３９．９４Å）であった。これはブチルアミン−ＨＴｉＮｂＯ₅ に比較して約２．１７３ｎｍ（２１．７３Å）と大きく拡大しており、５ＣＢが層間に挿入されたと考えることができる。この層間隔の変化は、５ＣＢの分子長１．６３９ｎｍ（１６．３９Å）（ＭＯＰＡＣによる計算値）よりも十分大きく、第一段階のインターカレーションで層間に層入したブチルアミンの無機層に対する傾斜角度が不変であるとすると、層間に５ＣＢは２分子層以上挿入されていることになる。ブチルアミンの傾斜角度が不変かつ５ＣＢが２分子層存在すると仮定し、５ＣＢの傾斜角度を図１０を参照して見積もると、ブチルアミン−ＨＴｉＮｂＯ₅ 単結晶の層間隔ｄ₁ ＝１．８２１ｎｍ（１８．２１Å）、５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ₅ 結晶の層間隔ｄ＝３．９９４ｎｍ（３９．９４Å）（熱処理条件１３０℃、２４時間の場合）、５ＣＢの分子長ａ＝１．６３９ｎｍ（１６．３９Å）、Δｄ＝ｄ−ｄ₁ ＝２．１７３ｎｍ（２１．７３Å）であるから、傾斜角度θ＝ａｒｃｓｉｎ（Δｄ／２ａ）＝ａｒｃｓｉｎ（２．１７３／２×１．６３９）＝４２°と見積もられる。
【００６４】
図１１に、ブチルアミン−ＨＴｉＮｂＯ₅ の層間に５ＣＢを挿入する際の反応時間と層間隔との関係を示す。ただし、反応温度は１３０℃とした。図１１より、層間隔は反応時間の増加に伴って増加しており、このことから、熱処理時間が増加するにつれて５ＣＢは層間に多量に挿入され、層間隔が拡大することがわかる。
【００６５】
ブチルアミン−ＨＴｉＮｂＯ₅ に５ＣＢが挿入されたことをさらに確認するために赤外（ＩＲ）測定を行った。図１２に、５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ₅ 単結晶（熱処理条件１３０℃、２４時間）のＩＲスペクトルを示す。この系においては、５ＣＢが挿入されたことを確認することは容易である。これは、５ＣＢには２２００ｃｍ^-1付近のシアノ基（Ｃ≡Ｎ）の伸縮振動に由来する明瞭なピークがあるが、ブチルアミン−ＨＴｉＮｂＯ₅ にはこれがないからである。図１２には明らかにシアノ基に由来するピークが存在しているので、５ＣＢが挿入されていることがわかる。
【００６６】
次に、この５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ₅ 結晶に電場印加を行った場合の変位について考察する。５ＣＢは正の誘電異方性を有する液晶であるので、電場を印加すると、分子の長軸が電場ベクトルに対して平行となるように配向する。電場を印加しない初期状態で無機層に対する５ＣＢ分子の傾斜角度が４２°の場合には、電場印加により傾斜角度が９０°へと変化すると、層間隔の増加は２．２ｎｍ（２２Å）となる。従って、この結晶では電場印加前に比べｃ軸方向に最大５４％もの極めて大きい伸張が得られることになる。
【００６７】
次に、この発明の第２の実施形態について説明する。この第２の実施形態においては、第１の実施形態においてゲスト有機物質として用いたｎ−ブチルアミンの代わりに４−アミノブトキシ−４’−シアノビフェニル（4-aminobutoxy-4 ’-cyanobiphenyl）（以下「ＡＢＣＢ」と呼ぶ）を用いる。
【００６８】
この第２の実施形態による無機有機複合材料の電圧無印加時における構造は、図２におけるブチルアミン層をＡＢＣＢ層で置き換えたものに相当する。
【００６９】
次に、この無機有機複合材料の製造方法について説明する。
この無機有機複合材料は、ＫＴｉＮｂＯ₅ 単結晶の作製、ＫＴｉＮｂＯ₅ 単結晶の処理によるＨＴｉＮｂＯ₅ 単結晶の作製およびＨＴｉＮｂＯ₅ 単結晶に対する二段階のインターカレーションの工程を経て製造されるが、ＫＴｉＮｂＯ₅ 単結晶の作製からＨＴｉＮｂＯ₅ 単結晶の作製までの工程は第１の実施形態と同様であるので説明を省略し、ＨＴｉＮｂＯ₅ 単結晶に対する二段階のインターカレーションの工程についてのみ説明する。
【００７０】
第一段階インターカレーション：ＡＢＣＢ−ＨＴｉＮｂＯ ₅ 単結晶の作製
第一段階インターカレーションで用いるＡＢＣＢの合成は、Kawasumiら（Mol.Cryst.Liq.Cryst., 281 (1996) 91.）によって報告されている手法を参考に行った。得られたＡＢＣＢを水／エタノール混合溶媒（Ｈ₂ Ｏ：Ｃ₂ Ｈ₅ ＯＨ＝１：１）に溶かし、０．１ｍｏｌ／ｌのＡＢＣＢ溶液を作製した。この溶液をサンプル管に入れ、これにＡＢＣＢ：ＨＴｉＮｂＯ₅ ＝１０：１となるようＨＴｉＮｂＯ結晶を入れた。各結晶の大きさは１〜２ｍｍ角で、厚さは０．１〜０．５ｍｍ程度であった。上記サンプル管を密閉し、オーブンの中に入れ、７０℃で１２時間の熱処理を行った。
【００７１】
この操作によって、ＡＢＣＢがＨＴｉＮｂＯ₅ の層間に挿入されたインターカレーション化合物（以下「ＡＢＣＢ−ＨＴｉＮｂＯ₅ 」と呼ぶ）の結晶が得られた。このＡＢＣＢ−ＨＴｉＮｂＯ₅ 単結晶のＸ線回折パターンを図１３に示す。図１３に示すように、（００１）に由来する回折ピークが見られ、（００２）回折ピークから計算される面間隔はｄ＝３．２９３ｎｍ（３２．９３Å）であった。これはＨＴｉＮｂＯ₅ のそれに比較して２．４４５ｎｍ（２４．４５Å）拡大しており、ＡＢＣＢが層間に挿入されたと考えることができる。層間に挿入されたＡＢＣＢ分子が無機層間で、2 分子層を形成していると仮定すると、ＡＢＣＢの分子長が１．６８２ｎｍ（１６．８２Å）（ＭＯＰＡＣによる計算値）であることから、その無機層に対する傾斜角度はａｒｃｓｉｎ^-1（２．４４５／（２×１．６８２））＝４７°と見積もられる。
【００７２】
次に、ＡＢＣＢ−ＨＴｉＮｂＯ₅ の組成を明らかにするために窒素の定量分析を行った。その結果得られた組成式は
（ＡＢＣＢ）_0.62ＨＴｉＮｂＯ₅
であった。
【００７３】
第二段階インターカレーション：５ＣＢ−ＡＢＣＢ−ＨＴｉＮｂＯ ₅ 単結晶の作製
第一段階インターカレーションを行ったＡＢＣＢ−ＨＴｉＮｂＯ₅ 単結晶に第二段階インターカレーションを行った。挿入物質は、第一の実施形態で用いたものと同じ室温ネマティック液晶５ＣＢである。
【００７４】
ＡＢＣＢ−ＨＴｉＮｂＯ₅ 単結晶を５ＣＢとともに、１３０℃で１２時間熱処理した試料（以下「５ＣＢ−ＡＢＣＢ−ＨＴｉＮｂＯ₅ 」と呼ぶ）のＸ線回折パターンを図１４に示す。同図のＸ線回折パターンからは（００１）の回折ピークが見られ、（００２）回折ピークから計算される層間隔はｄ＝３．８５５ｎｍ（３８．５５Å）であった。これは、ＡＢＣＢ−ＨＴｉＮｂＯ₅ に比較して約０．５６２ｎｍ（５．６２Å）拡大しており、５ＣＢが層間に挿入されたと考えることができる。層間隔の変化は５ＣＢの分子長（１．６３９ｎｍ（１６．３９Å））よりもかなり小さいので、挿入されている５ＣＢは１分子層を形成していることが予想される。層間の５ＣＢが１分子層を成し、かつＡＢＣＢの傾斜角度が不変であると仮定すると、第二段階目のインターカレーションプロセスにより層間に挿入された５ＣＢの傾斜角度はａｒｃｓｉｎ^-1（０．５６２／１．６３９）＝２０°と見積もられる。
【００７５】
図１５に、ＡＢＣＢ−ＨＴｉＮｂＯ₅ の層間に５ＣＢを挿入する際の反応時間と層間隔との関係を示す。図１５より、層間隔は反応時間に依存して増加する傾向を示しており、このことから、反応時間が増加するにつれて５ＣＢは層間に多量に挿入され、層間隔が拡大することがわかる。
次に、この５ＣＢ−ＡＢＣＢ−ＨＴｉＮｂＯ₅ 単結晶に電場印加を行った場合の変位について考察する。層間に５ＣＢが1 分子層入っており、電場を印加しない初期状態で無機層に対する５ＣＢ分子の傾斜角度が２０°と仮定した場合には、電場印加により傾斜角度が９０°へと変化すると層間隔の増加は１．０７７ｎｍ（１０．７７Å）となり、２８％の伸びが得られる。
【００７６】
次に、この発明の第３の実施形態について説明する。この第３の実施形態においては、この発明による無機有機複合材料（インターカレーション化合物）を用いたアクチュエータについて説明する。
【００７７】
図１６は、この第３の実施形態によるアクチュエータの基本ユニットを示す。
このアクチュエータで使用する無機有機複合材料（インターカレーション化合物）は、第１の実施形態または第２の実施形態のものでもよいし、５ＣＢ以外の液晶分子やＨＴｉＮｂＯ₅ 以外の無機層状物質を用いたものでもよく、必要に応じて選ばれる。このアクチュエータにおいては、円柱、直方体などの柱状の無機有機複合材料２１の上下両面に電極２２、２３が設けられ、これらの電極２２、２３からそれぞれリード線２４、２５が取り出されている。無機有機複合材料２１は、大きな変位を効率的に得ることができるように、好適にはｃ軸方向に高度に配向したバルク結晶や薄膜あるいは厚膜の形状を有しており、より具体的には単結晶、高ｃ軸配向多結晶体、高ｃ軸配向薄膜などである。無機有機複合材料２１および電極２２、２３の外周面は、無機有機複合材料２１の無機層間に存在する液晶分子の漏洩や無機有機複合材料２１の伸縮に伴う無機層の剥離などを防止するとともに、形状を保持する目的で、有機高分子によるコーティング２６が施されている。この有機高分子によるコーティング２６の材料は、耐久性に優れ、無機有機複合材料の駆動時に負担とならないように伸縮性、柔軟性を有しているものであれば、基本的にはどのようなものであってもよいが、具体的には、例えばシリコーンゴム、フッ素ゴム、クロロプレンゴムなどが用いられる。
【００７８】
図１７はこの発明の第４の実施形態による積層アクチュエータを示す。図１７に示すように、この積層アクチュエータは、十分な変位が得られるように、図１６に示すアクチュエータの基本ユニットを、その伸縮方向であるｃ軸方向に複数積層したものである。ここでは、複数のアクチュエータをその伸縮方向に積層していることが重要であって、積層アクチュエータの全体形状は、例えば直方体、円柱などの任意の形状であってよい。図１７では基本ユニットの数が４の場合が示されているが、基本ユニットの数は必要に応じて選択される。各ユニットのアクチュエータには、リード線２４、２５を通じて外部から電圧が印加される。
【００７９】
図１８はこの発明の第５の実施形態による繊維状アクチュエータを示す。図１８に示すように、この繊維状アクチュエータは、図１７に示す積層アクチュエータの段数を十分に多くして全体として繊維状の形態としたものを基本とし、それらを並列に複数本束ねたものである。
【００８０】
この第５の実施形態によれば、繊維状の積層アクチュエータを複数本並列に束ねてアクチュエータを構成していることにより、アクチュエータの発生力および強度を飛躍的に増すことができる。また、このアクチュエータの一本一本の繊維は柔軟であり、電圧印加により協同的に駆動するので、生物の筋肉を模倣したアクチュエータとして好適なものとなる。
【００８１】
以上の第３、第４および第５の実施形態によれば、柔軟性、高速応答性、大変位といった特徴を併せ持つ高性能のアクチュエータが実現され、これは例えばロボティクス、医療などの分野に好適に利用することができる。
ここで、これらの第３、第４および第５の実施形態によるアクチュエータを、特開平０５−１１０１５３号公報および特開平０６−１２５１２０号公報に開示された変位素子と比較すると、次のような多くの利点を有する。
（１）上記公報に開示された素子は全固体型であるが、第３、第４および第５の実施形態によるアクチュエータは無機層状物質の層間に液晶が挿入されているので全固体ではない。ここが最大の相違点である。液晶との複合化は素子に柔軟性を与えるので、生体筋のような柔軟な特性を必要とする人工素子が得られる。これは近年発展してきた自律型ロボットの開発において大きな利点となるものである。
（２）上記公報に開示された素子では、その実施例においてインターカレーション反応を一段階しか行っていない。一方、第３、第４および第５の実施形態によるアクチュエータでは、それを構成する無機有機複合材料の製造に際して二段階以上のインターカレーションを行っている。この方法によれば、大部分の液晶分子を挿入することができる、液晶分子の挿入量が挿入温度や時間により容易に制御できる、などの利点を得ることができる。
（３）上記公報に開示された素子では、その実施例においてインターカレーション物質の粉末を用いているが、これではインターカレーション物質に特有な異方性を十分に生かすことはできない。一方、第３、第４および第５の実施形態によるアクチュエータでは、変位を得るのに最適なマトリックスである単結晶を用いている。
【００８２】
図１９はこの発明の第６の実施形態による駆動システムを示す。この駆動システムは人工拮抗筋の駆動システムである。
図１９に示すように、この駆動システムは、二つの人工筋肉６１、６２を組み合わせたものである。これらの人工筋肉６１、６２としては、例えば、第５の実施形態と同様なアクチュエータを用いることができる。人工筋肉６１は容器６３内に収納されており、人工筋肉６１の両端の伝達棒６４は容器６３の外部に引き出されている。同様に、人工筋肉６２は容器６５内に収納されており、人工筋肉６２の両端の伝達棒６６は容器６５の外部に引き出されている。人工筋肉６１、６２の一端の伝達棒６４、６６は支柱６７と接続されている。同様に、人工筋肉６１、６２の他端の伝達棒６４、６６は支柱６８と接続されている。これらの支柱６７、６８は関節６９を介して相互に結合されており、この関節６９を中心として回転することができるようになっている。
【００８３】
この第６の実施形態においては、生物の骨に当たる支柱６７、６８に対して人工筋肉６１、６２が拮抗した動作を行う。すなわち、人工筋肉６１、６２の協調動作により、拮抗筋と類似の動作を行うことができる。例えば、人工筋肉６１、６２の電圧無印加時の長さがいずれもＬで等しく、それらを構成する各アクチュエータの電極間に電圧Ｖ₁ を印加したときの伸長量がΔＬである場合、例えば人工筋肉６１、６２の長さがＬ＋ΔＬ／２のときを基準にすると、図１９に示した状態では、人工筋肉６１は収縮しているのに対し、人工筋肉６２はこれと逆に伸長している。この場合、人工筋肉６１を構成する各アクチュエータの電極間に印加されている電圧Ｖ₂ は０＜Ｖ₂ ＜Ｖ₁ であり、人工筋肉６２を構成する各アクチュエータの電極間に印加されている電圧Ｖ₃ はＶ₁ ＜Ｖ₃ である。
【００８４】
この第５の実施形態によれば、第３、第４または第５の実施形態と同様な利点を得ることができるほか、二つの人工筋肉６１、６２を組み合わせて拮抗筋を構成しているので、人工筋肉を単独で駆動させるよりもバランスの取れた動きが可能となるという利点を得ることができる。
【００８５】
以上、この発明の実施形態について具体的に説明したが、この発明は、上述の実施形態に限定されるものではなく、この発明の技術的思想に基づく各種の変形が可能である。
【００８６】
例えば、上述の実施形態において挙げた数値、材料、構造、形状、プロセスなどはあくまでも例にすぎず、必要に応じて、これらと異なる数値、材料、構造、形状、プロセスなどを用いてもよい。
【００８７】
【発明の効果】
以上説明したように、この発明によれば、ホスト無機層状物質とこのホスト無機層状物質の層間に存在する少なくとも一種類以上のゲスト有機物質とからなる無機有機複合材料において、少なくとも一種類のゲスト有機物質が液晶性を有する有機分子を含むことにより、強靭性、柔軟性、得られる変位の大きさ、応答速度、変位を取り出す際のエネルギー効率などの諸点で満足し得る性能を有する無機有機複合材料、アクチュエータおよび人工筋肉を実現することができる。そして、これらの無機有機複合材料、アクチュエータおよび人工筋肉をインターカレーションの手法により容易に製造することができる。
【図面の簡単な説明】
【図１】無機層状物質の層間に液晶を挿入したこの発明による無機有機複合材料の電圧印加による駆動メカニズムを説明するための略線図である。
【図２】この発明の第１の実施形態による無機有機複合材料の結晶構造を示す略線図である。
【図３】ＫＴｉＮｂＯ₅ の結晶構造を示す略線図である。
【図４】この発明の第１の実施形態において作製されたＫＴｉＮｂＯ₅ 結晶のＸ線回折パターンを示す略線図である。
【図５】ＨＴｉＮｂＯ₅ の結晶構造を示す略線図である。
【図６】この発明の第１の実施形態において作製されたＨＴｉＮｂＯ₅ 結晶のＸ線回折パターンを示す略線図である。
【図７】この発明の第１の実施形態において作製されたブチルアミン−ＨＴｉＮｂＯ₅ 結晶のＸ線回折パターンを示す略線図である。
【図８】この発明の第１の実施形態において作製されたブチルアミン−ＨＴｉＮｂＯ₅ 結晶の層間におけるブチルアミンの傾斜角度を見積もるための略線図である。
【図９】この発明の第１の実施形態において作製された５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ₅ 結晶のＸ線回折パターンを示す略線図である。
【図１０】この発明の第１の実施形態において作製された５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ₅ 結晶の層間における５ＣＢの傾斜角度を見積もるための略線図である。
【図１１】この発明の第１の実施形態において作製された５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ₅ 結晶の層間隔と反応時間との関係を示す略線図である。
【図１２】この発明の第１の実施形態において作製された５ＣＢ−ブチルアミン−ＨＴｉＮｂＯ₅ 結晶の赤外スペクトルを示す略線図である。
【図１３】この発明の第２の実施形態において作製されたＡＢＣＢ−ＨＴｉＮｂＯ₅ 結晶のＸ線回折パターンを示す略線図である。
【図１４】この発明の第２の実施形態において作製された５ＣＢ−ＡＢＣＢ−ＨＴｉＮｂＯ₅ 結晶のＸ線回折パターンを示す略線図である。
【図１５】この発明の第２の実施形態において作製された５ＣＢ−ＡＢＣＢ−ＨＴｉＮｂＯ₅ 結晶の層間隔と反応時間との関係を示す略線図である。
【図１６】この発明の第３の実施形態によるアクチュエータを示す断面図である。
【図１７】この発明の第４の実施形態による積層アクチュエータを示す断面図である。
【図１８】この発明の第５の実施形態による繊維状アクチュエータを示す略線図である。
【図１９】この発明の第６の実施形態による駆動システムを示す断面図である。
【符号の説明】
１１、１２・・・無機層、１３、１４・・・ブチルアミン層、１５、１６・・・５ＣＢ層、２１・・・無機有機複合材料、２２、２３・・・電極、２４、２５・・・リード線、２６・・・有機高分子によるコーティング、６１、６２・・・人工筋肉[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inorganic-organic composite material and a manufacturing method thereof, an actuator and a manufacturing method thereof, and an artificial muscle and a manufacturing method thereof. More specifically, the present invention is useful for realizing a device that generates displacement in response to an external field, particularly an electric field, and is suitable for use in fields such as electronics, robotics, and medical care. is there.
[0002]
[Prior art]
As actuators that are currently in practical use, most of them are electromagnetic motors and electrostrictive elements (piezoelectric elements) driven by electric drive, hydraulic actuators and pneumatic actuators driven by fluid pressure. In fact, as long as it is used in various automated equipment and various transport equipment in factories, these existing actuators have practically sufficient characteristics. However, for example, in an autonomous robot actuator that has been urgently developed, it is necessary for a plurality of actuators to perform an operation having a three-dimensional degree of freedom in cooperation. Since the generated force and the self-weight are loads of other actuators, the control difficulty and the total weight increase dramatically as the degree of freedom increases (Toshin Takamori, “Actuator Revolution” Industrial Research Committee, 1987).
[0003]
In such use, it can be said that the muscle of the living body is an excellent actuator with a good balance. Specifically, the displacement is 50% in the shrinking direction, the response time is 30 ms, and the generated tension is 2 to 10 kg / cm.²The generated power is 0.1 to 0.3 W / g at the maximum per unit weight, and no actuator satisfying all of these has been developed at present (Applied Physics Vol. 60, No. 3, (1991) p. 258). Furthermore, flexibility is also a major characteristic of living muscles.
[0004]
Stimulus-responsive polymer gels have recently attracted attention as artificial muscles similar to living muscles, and research in this field is being actively conducted. This polymer gel is driven by a change in volume of the gel caused by movement of the solvent contained in the gel due to changes in the external environment such as electric field, temperature, pH, and solution concentration. This actuator system is light and flexible, and has many advantages such as no noise and no generation of exhaust gas associated with combustion. However, the following problems have been pointed out as main problems in the polymer gel currently under development.
[0005]
(1) Since the structure does not have anisotropy, it becomes three-dimensional expansion / contraction (swelling / contraction), and the energy efficiency is lower than that of a one-dimensional expansion / contraction structure (eg, biological muscle). .
(2) Mechanical strength and durability are low.
(3) Since the driving mechanism is volume change due to solvent movement, the response speed is limited by the diffusion of the solvent and is slow.
[0006]
As a solution to the problem (3), a liquid crystal actuator using a polymer liquid crystal or liquid crystal elastomer driven by an electric field as a main component has been reported (for example, Japanese Patent Laid-Open Nos. 3-5720 and 3). No. 7079, JP-A-6-324312). Since the driving mechanism of this liquid crystal actuator is to cause the deformation by causing the orientation change due to the electric field of the liquid crystal to be transmitted to the polymer chain, there is an advantage that the response speed is faster than that controlled by solvent diffusion. More specifically, in JP-A-3-5720 and JP-A-3-7079, a liquid crystal actuator having a structure in which a polymer liquid crystal or a liquid crystal elastomer is sandwiched between two electrodes is disclosed in JP-A-6-324312. An actuator using a so-called liquid crystal gel in which a liquid crystal elastomer is swollen by a low molecular liquid crystal substance is disclosed. However, in these liquid crystal actuators, since the polymer portion serving as a matrix does not have anisotropy, it is considered that the efficiency when taking out force and displacement is lowered.
[0007]
On the other hand, one of the actuators currently in practical use is an electrostrictive element that is driven by application of an electric field to generate distortion. This electrostrictive element is generally formed of a ceramic mainly composed of lead zirconate titanate (PZT), which is an inorganic material, and has the advantages of excellent strength and durability, and high response speed. It has a problem that it is small (about 0.1%) and lacks flexibility.
[0008]
However, according to the knowledge of the present inventors, since conventional liquid crystal actuators use a polymer as a matrix, the energy accompanying the electric field alignment of liquid crystal molecules cannot be efficiently converted into mechanical energy. In order to efficiently convert energy into force, it is conceivable to use a matrix having a structural anisotropy that causes expansion and contraction in only one direction. Not reported until. Furthermore, the conventional electrostrictive inorganic actuator has problems that it is poor in flexibility and displacement is small.
[0009]
Further, a displacement element using an inorganic / organic composite intercalation substance is disclosed in Japanese Patent Laid-Open Nos. 05-110153 and 06-125120. These displacement elements are driven by changing the orientation angle of the polar organic material by applying an external electric field to the compound in which the polar organic material is inserted between the layers of the inorganic layered material. However, these displacement elements are all solid, and lack flexibility as with the electrostrictive inorganic actuator described above.
[0010]
Techniques for realizing an actuator using an intercalation technique are disclosed in Japanese Patent Laid-Open Nos. 2-131376 and 4-12785. Both of these actuators use a change in volume due to the guest ions in and out of the host material as a driving force. More specifically, the actuator disclosed in Japanese Patent Laid-Open No. 2-131376 has a structure in which polyethylene oxide as an electrolyte is sandwiched between graphite intercalation compounds, and bending occurs when Li is transported between the layers. is there. On the other hand, the actuator disclosed in Japanese Patent Application Laid-Open No. Hei 4-12785 has a positive / negative electrode with Ag._0.7V₂O_Five4AgI-Ag as a solid electrolyte₂WO_FourIs used. None of these publications mention liquid crystal molecules as well as other organic molecules as guests, and are considered to be different from the present invention.
[0011]
Regarding compounding of a liquid crystal and an intercalation compound (for example, clay mineral), Japanese Patent Application Laid-Open No. 07-278549, Japanese Patent Application Laid-Open No. 07-318982, Japanese Patent Application Laid-Open No. 08-045662, and Japanese Patent Application Laid-Open No. 08-015663. JP-A-08-269453, JP-A-08-302351 and JP-A-10-148849. In these publications, liquid crystal compositions that can be obtained by imparting liquid crystal affinity to flat shaped particles such as clay minerals and dispersing them in a liquid crystal matrix, and light-scattering dimmers that have memory and high-speed response characteristics Although it is disclosed for application to a recording medium / recording element, a temperature-responsive optical shutter, etc., it does not mention application to an actuator or displacement.
[0012]
[Problems to be solved by the invention]
As described above, until now, it has been difficult to obtain satisfactory performance in terms of toughness, flexibility, magnitude of displacement obtained, response speed, energy efficiency in taking out displacement, and the like.
Therefore, the problem to be solved by the present invention is to improve the above-mentioned drawbacks of the prior art by compositing an inorganic layered substance and an organic molecule exhibiting liquid crystallinity at the molecular level by an intercalation technique. , Novel inorganic-organic composite material capable of obtaining satisfactory performance in terms of toughness, flexibility, magnitude of displacement obtained, response speed, energy efficiency in taking out displacement, and the like, and a method for producing the same It is an object of the present invention to provide a novel actuator and artificial muscle using an organic composite material, and a production method thereof.
[0013]
[Means for Solving the Problems]
In order to solve the above-described problems of the prior art, the present inventors have conducted intensive studies from both theoretical and experimental viewpoints. As a result, in order to solve the above-mentioned problems all at once, an inorganic organic composite material in which a liquid crystal is inserted between layers of an inorganic layered substance by an intercalation technique, and the inorganic layered substance and liquid crystal molecules are combined at the molecular level ( We have reached the conclusion that it is effective to construct an actuator using an intercalation compound), and have conducted extensive research to realize the inorganic-organic composite material and succeeded in the synthesis. Then, using this inorganic-organic composite material, an actuator having a completely new configuration that combines the toughness of the inorganic substance and the flexibility of the organic substance was created. Until now, there has been no report on the use of a compound obtained by intercalating liquid crystal in such an inorganic layered substance for an actuator.
[0014]
That is, in order to solve the above problem, the first invention of the present invention is:
In an inorganic-organic composite material comprising a host inorganic layered substance and at least one kind of guest organic substance present between the host inorganic layered substance,
At least one kind of guest organic substance is composed of organic molecules having liquid crystallinity
It is characterized by this.
[0015]
The second invention of this invention is:
A method for producing an inorganic-organic composite material comprising a host inorganic layered substance and at least one kind of guest organic substance existing between the host inorganic layered substances, wherein at least one kind of guest organic substance is composed of organic molecules having liquid crystallinity Because
Intercalated guest organic material between layers of host inorganic layered material
It is characterized by this.
[0016]
The third invention of the present invention is:
An inorganic organic composite material comprising a host inorganic layered substance and at least one kind of guest organic substance existing between the layers of the host inorganic layered substance, wherein at least one kind of guest organic substance is composed of organic molecules having liquid crystallinity was used.
This is an actuator.
[0017]
The fourth invention of the present invention is:
An inorganic organic composite material comprising a host inorganic layered substance and at least one kind of guest organic substance existing between the layers of the host inorganic layered substance, wherein at least one kind of guest organic substance is composed of organic molecules having liquid crystallinity was used. An actuator manufacturing method comprising:
Intercalated guest organic material between layers of host inorganic layered material
It is characterized by this.
[0018]
The fifth invention of the present invention is:
An inorganic organic composite material comprising a host inorganic layered substance and at least one kind of guest organic substance existing between the layers of the host inorganic layered substance, wherein at least one kind of guest organic substance is composed of organic molecules having liquid crystallinity was used.
It is an artificial muscle characterized by this.
[0019]
The sixth invention of the present invention is:
An inorganic organic composite material comprising a host inorganic layered substance and at least one kind of guest organic substance existing between the layers of the host inorganic layered substance, wherein at least one type of guest organic substance is composed of organic molecules having liquid crystallinity is used. A method for manufacturing artificial muscle,
Intercalated guest organic material between layers of host inorganic layered material
It is characterized by this.
[0020]
In the present invention, the “organic molecule having liquid crystallinity” refers to an organic molecule exhibiting liquid crystallinity in a certain finite temperature range, and may take any of a nematic phase, a cholesteric phase, and a smectic phase.
[0021]
In this invention, the inorganic-organic composite material is a material in which the guest organic substance existing between the layers of the host inorganic layered substance is at least one organic molecular layer composed of organic molecules having liquid crystallinity. There may be only an organic molecular layer composed of organic molecules having liquid crystallinity between layers, or organic molecules having liquid crystallinity in which guest organic substances existing between the layers of the host inorganic layered substance are arranged in parallel to the layers. There may be a plurality of organic molecular layers including at least one organic molecular layer comprising The plurality of organic molecular layers in the latter case include at least two types of organic molecular layers, and typically, the first organic molecular layer, the second organic molecular layer different from the first organic molecular layer, and the first organic molecular layer It consists of a third organic molecular layer identical to one organic molecular layer, and the second organic molecular layer consists of organic molecules having liquid crystallinity.
[0022]
The plurality of organic molecular layers are preferably composed of at least one organic molecular layer composed of organic molecules having liquid crystallinity, from the viewpoint of easily producing an inorganic-organic composite material using an intercalation technique. And a pair of organic molecular layers made of organic molecules having affinity for organic molecules having liquid crystallinity, sandwiching the organic molecular layer. Specifically, for example, the plurality of organic molecular layers include a first organic molecular layer, a second organic molecular layer different from the first organic molecular layer, and a third organic molecule layer that is the same as the first organic molecular layer. The second organic molecular layer is composed of organic molecules having liquid crystallinity, and the first organic molecular layer and the third organic molecular layer have an affinity for the organic molecules having liquid crystallinity. It consists of organic molecules. In this case, preferably, the organic molecule having liquid crystallinity and the organic molecule having affinity for the organic molecule having liquid crystallinity have at least one identical functional group and / or a structure similar to each other. This functional group is, for example, at least one functional group selected from the group consisting of an amino group, an alkyl group, an allyl group, a sulfone group, a cyano group, and a carbonyl group.
[0023]
In this invention, from the viewpoint of causing the orientation change of the organic molecule having liquid crystallinity by applying an electric field, preferably, at least one polar functional group is bonded to at least one carbon position of the organic molecule having liquid crystallinity. Yes. This polar functional group is, for example, —NH₂, NR₂(Where R is an alkyl group), -NPh₂(Where Ph is a phenyl group), -SO_ThreeAt least one polar functional group selected from the group consisting of H and CN.
[0024]
As the host inorganic layered substance, basically any material can be used as long as it can insert liquid crystal organic molecules between the layers. For example, in the case of an inorganic layered substance capable of inserting an amine-based molecule, it is possible to insert this liquid crystal organic molecule by a two-step intercalation method. Inorganic layered materials that have been reported to intercalate amine-based molecules include layered clay minerals such as smectite, vermiculite, and mica, and TaS.₂Metal chalcogenides such as, metal oxyhalides such as FeOCl, V₂Metal oxides such as O, Zr (HPO_Four)₂・ NH₂There are metal phosphates such as O (zirconium phosphate). Therefore, it is possible to insert organic molecules having liquid crystallinity at least between the layers of the inorganic layered substance. These host inorganic layered materials are summarized as follows. Most of these layered inorganic substances are similar in properties to the layered inorganic substances described above, and therefore it is considered possible to intercalate amine-based molecules and further intercalate organic molecules having liquid crystallinity.
[0025]
(1) Layered perovskite and niobium
KLaNb₂O₇, KCa₂Nb_ThreeO_Ten, RbCa₂Nb_ThreeO_Ten, CsCa₂Nb_ThreeO_Ten, KNaCa₂Nb_FourO₁₃
(2) Layered perovskite copper series
Bi₂Sr₂CaCu₂O₈, Bi₂Sr₂Ca₂Cu_ThreeO_Ten
(3) Layered titanium / niobate
KTiNbO_Five, K₂Ti_FourO₉, K_FourNb₆O₁₇
(4) Layered rock salt oxide
LiCoO₂LiNiO₂
(5) Transition metal oxide bronze system
MoO_Three, V₂O_Five, WO_Three, ReO_Three
(6) Transition metal oxo chloride
FeOCl, VOCl, CrOCl
(7) Layered polysilicate
Na₂O-4SiO₂-7H₂O etc.
(8) Layered clay mineral
Smectite, vermiculite, mica mica, etc.
(9) Hydrotalcite
Mg₆Al₂(OH)₁₆CO_Three-H₂O
(10) Transition metal chalcogenides
TaSe₂, TaS₂, MoS₂, VSe₂
(11) Zirconium phosphate
Zr (HPO_Four)₂・ NH₂O
(12) Graphite
C
Etc. Many of these inorganic substances have strong two-dimensionality and are easily oriented in the c-axis direction during crystal synthesis. Even if large crystals cannot be obtained, a highly c-axis oriented film is often obtained by casting a solution containing the microcrystals.
[0026]
This host inorganic layered substance changes the alignment characteristics of liquid crystalline organic molecules existing between the layers of the inorganic layered substance by applying a voltage, and changes the layer spacing. For extraction, it is most preferably a single crystal, typically a single crystal with a side length of 1 μm or more, but preferably has a highly oriented bulk polycrystalline or thin film shape, preferably for c-axis orientation. It may be a thing.
[0027]
Next, the guest organic substance composed of organic molecules having liquid crystallinity can be basically used as long as it is composed of organic molecules that exhibit liquid crystallinity in a certain finite temperature range and undergo alignment change upon application of voltage. Good. In particular, for organic molecules having liquid crystallinity inserted after the second stage, organic molecules having an amino group and having the same functional group or similar structure as the organic molecule having liquid crystallinity are put in the first stage. The idea is that most organic molecules with liquid crystallinity can be inserted. As typical examples of such organic molecules having liquid crystallinity, for example,
[Chemical 1]

[Chemical 2]

[Chemical Formula 3]

Schiff base system shown in
[Formula 4]

[Chemical formula 5]

[Chemical 6]

[Chemical 7]

[Chemical 8]

[Chemical 9]

[Chemical Formula 10]

Embedded image

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Benzoic acid ester system shown in
Embedded image

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Biphenyl system shown in
Embedded image

The terphenyl system shown in
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Cyclohexyl carboxylic acid ester system shown in
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Phenylcyclohexane system shown in
Embedded image

Biphenylcyclohexane system shown in
Embedded image

Cyclohexylcyclohexane system shown in
Embedded image

Biphenylcyclohexane system shown in
Embedded image

Embedded image

Cyclohexyl cyclohexane ester system shown in
Embedded image

Biphenylcyclohexane system shown in
Embedded image

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Pyrimidine series,
Embedded image

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The dioxane system shown in
Embedded image

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Embedded image

Cyclohexyl carboxylic acid ester system shown in
Embedded image

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Cyclohexyl ethane system shown in
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Azoxy-based,
Embedded image

Azo system shown in
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There are cholesterol systems and so on. Furthermore, a liquid crystal molecule having asymmetric carbon and exhibiting ferroelectricity or antiferroelectricity, a polymer liquid crystal having a mesogen group in the main chain or side chain, a liquid crystal molecule using an organometallic complex, etc. can be used. Note that one kind of liquid crystal may be used alone, or two or more kinds of liquid crystals may be mixed and used.
[0028]
In this invention, the inorganic organic composite material in which the guest organic substance existing between the layers of the host inorganic layered substance is at least one organic molecular layer composed of organic molecules having liquid crystallinity is used. It can be produced by directly intercalating between the layers of the layered material. For example, the host inorganic layered material is HTiNbO._FiveConsidering this case, this HTiNbO_FiveHas a property of a solid acid, so that basic organic molecules, particularly amine-based molecules can be easily intercalated, which is a generally known fact. Therefore, if it is an amine-based liquid crystal, HTiNbO_FiveIt is considered that it can be directly inserted between the layers with one step of intercalation. Examples of amine-based liquid crystal molecules are as follows. These are compounds in which an asymmetric tertiary amine is bonded to a benzene ring or a cyclohexane ring.
[0029]
Embedded image

Embedded image

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[0030]
These amine liquid crystals are converted into HTiNbO._FiveAs a method of intercalating directly between crystal layers, specifically, for example,
(1) An amine-based liquid crystal is heated to an isotropic liquid, and HTiNbO is contained therein._FiveHow to put crystals
(2) Amine-based liquid crystal is dissolved in a solvent (for example, water, ethanol, or a mixed solvent thereof), and HTiNbO is dissolved therein._FiveHow to put crystals
Can be used.
As described above, if an amine liquid crystal and an appropriate insertion method are selected, liquid crystal molecules can be directly inserted between inorganic layers without using a two-step method.
[0031]
However, it may not be easy to directly insert liquid crystal molecules between layers of inorganic layered material. In that case, two or more stages of intercalation are performed. For example, in the first stage of intercalation, organic molecules that are easily intercalated and have affinity for liquid crystals are inserted into the inorganic layered material. The intercalation compound that has undergone this process can insert liquid crystal molecules in the second-stage intercalation process. For example, as an inorganic layered material, HTiNbO_Five(KTiNbO_FiveIs obtained by treating with hydrochloric acid), an organic substance having an amino group (for example, n-butylamine) is easily inserted in the first stage of intercalation. When the organic substance having an amino group has a good affinity with, for example, a cyanobiphenyl liquid crystal, the liquid crystal can be inserted between the layers by the second stage intercalation.
[0032]
That is, when it is difficult to directly intercalate organic molecules having liquid crystallinity between the layers of the host inorganic layered substance, an inorganic / organic composite material is produced by performing intercalation in two or more stages. Specifically, the guest organic material present between the layers of the host inorganic layered material is a plurality of organic molecular layers including at least one organic molecular layer composed of organic molecules having liquid crystallinity arranged in parallel with the layer. The method for producing an inorganic-organic composite material includes a step of intercalating an organic molecule layer other than at least one organic molecule layer composed of organic molecules having liquid crystallinity among a plurality of organic molecule layers between layers of a host inorganic layered material, and And intercalating at least one organic molecular layer composed of organic molecules having liquid crystallinity among the plurality of organic molecular layers between the layers of the host inorganic layered material. Among these, in particular, the plurality of organic molecular layers includes a first organic molecular layer, a second organic molecular layer different from the first organic molecular layer, and a third organic molecular layer identical to the first organic molecular layer. The method for producing an inorganic-organic composite material includes a step of intercalating a first organic molecular layer and a third organic molecular layer between layers of a host inorganic layered material, and a second organic molecular layer between layers of a host inorganic layered material. And intercalating.
[0033]
In addition, a plurality of organic molecular layers are a pair of organic molecules having affinity for organic molecules having liquid crystallinity and sandwiching at least one organic molecular layer made of organic molecules having liquid crystalline properties and the organic molecular layer. A method for producing an inorganic organic composite material including an organic molecular layer includes a step of intercalating a pair of organic molecular layers composed of organic molecules having affinity for organic molecules having liquid crystallinity between layers of a host inorganic layered substance. And a step of intercalating at least one organic molecular layer made of organic molecules having liquid crystallinity between the layers of the host inorganic layered material. Among these, in particular, the plurality of organic molecular layers are composed of a first organic molecular layer, a second organic molecular layer different from the first organic molecular layer, and a third organic molecular layer identical to the first organic molecular layer. The second organic molecular layer is composed of organic molecules having liquid crystallinity, and the first organic molecular layer and the third organic molecular layer are composed of organic molecules having affinity for organic molecules having liquid crystallinity. The method for producing a composite material includes a step of intercalating a first organic molecular layer and a third organic molecular layer between layers of a host inorganic layered material, and a second organic molecular layer interposed between layers of a host inorganic layered material. And a curating step.
[0034]
Here, the function of the organic molecule having affinity for the organic molecule having liquid crystallinity inserted by the first stage intercalation will be described. In general, a compound having a similar functional group (for example, an amino group, an alkyl group, an allyl group, a sulfone group, a cyano group, a carbonyl group, etc.) exhibits similar properties, and the more similar the structure is, It tends to be similar in nature. As a result, when liquids or liquid crystals of compounds having similar functional groups and structures are brought into contact with each other, mixing easily occurs between them. Such a state is said to have high (good) affinity between the compounds. For example, it is considered that the organic molecule group having a cyanobiphenyl group has a high affinity for the cyanobiphenyl-based liquid crystal. Furthermore, it is considered that the affinity is relatively high even if only a cyano group is used instead of cyanobiphenyl. From the above, in order to intercalate liquid crystal molecules between inorganic layers, it is considered that organic molecules having the following characteristics should be inserted at the first stage and liquid crystal molecules should be inserted after the second stage.
(1) It has the same functional group as the liquid crystal molecules inserted after the second stage
(2) The structure is similar to the liquid crystal molecules inserted after the second stage
[0035]
When producing an inorganic-organic composite material, typically, the host inorganic layered substance is brought into contact with a solution or melt of a predetermined organic substance and held at a predetermined temperature for a predetermined period of time, thereby interposing the layer of the host inorganic layered substance. The guest organic material is intercalated, and if necessary, this process is performed several times with different types of organic materials. More specifically, the guest organic material existing between the layers of the host inorganic layered material is a plurality of organic molecular layers including at least one organic molecular layer composed of organic molecules having liquid crystallinity arranged in parallel with the layer. A method for producing an inorganic-organic composite material includes a step of bringing a host inorganic layered substance into contact with a solution or melt of a first organic substance and holding it at a predetermined temperature for a predetermined time, so that a plurality of layers are provided between the layers of the host inorganic layered substance. A step of intercalating an organic molecule layer other than at least one organic molecule layer composed of organic molecules having liquid crystallinity in the organic molecule layer, and contacting the host inorganic layered substance with a solution or melt of the second organic substance And holding at a predetermined temperature for a predetermined time, at least one layer composed of organic molecules having liquid crystallinity among the plurality of organic molecular layers between the layers of the host inorganic layered substance. And a step of intercalating molecular layer. Among these, in particular, the plurality of organic molecular layers includes a first organic molecular layer, a second organic molecular layer different from the first organic molecular layer, and a third organic molecular layer identical to the first organic molecular layer. In the method for producing an inorganic-organic composite material, the host inorganic layered substance is brought into contact with a solution or melt of the first organic substance and held at a predetermined temperature for a predetermined time, so that the first layer is formed between the layers of the host inorganic layered substance. The step of intercalating the organic molecular layer and the third organic molecular layer, and bringing the host inorganic layered substance into contact with the solution or melt of the second organic substance and holding the host at a predetermined temperature for a predetermined time. And a step of intercalating the second organic molecular layer between the layers of the inorganic layered material.
[0036]
In addition, a plurality of organic molecular layers are a pair of organic molecules having affinity for organic molecules having liquid crystallinity and sandwiching at least one organic molecular layer made of organic molecules having liquid crystalline properties and the organic molecular layer. A method for producing an inorganic organic composite material including an organic molecular layer includes: bringing a host inorganic layered substance into contact with a solution or melt of a first organic substance and holding the host inorganic layered substance at a predetermined temperature for a predetermined time. A step of intercalating a pair of organic molecular layers composed of organic molecules having affinity for organic molecules having liquid crystallinity between the layers, and contacting the host inorganic layered material with a solution or melt of the second organic material And at least one organic molecular layer composed of organic molecules having liquid crystallinity is intercalated between the layers of the host inorganic layered substance by holding at a predetermined temperature for a predetermined time. And a degree. Among these, in particular, the plurality of organic molecular layers are composed of a first organic molecular layer, a second organic molecular layer different from the first organic molecular layer, and a third organic molecular layer identical to the first organic molecular layer. The second organic molecular layer is composed of organic molecules having liquid crystallinity, and the first organic molecular layer and the third organic molecular layer are composed of organic molecules having affinity for organic molecules having liquid crystallinity. The method for producing a composite material includes the step of bringing a host inorganic layered substance into contact with a solution or melt of a first organic substance and holding it at a predetermined temperature for a predetermined time, so that the first organic molecule is placed between the layers of the host inorganic layered substance. A step of intercalating the layer and the third organic molecular layer, and contacting the host inorganic layered material with a solution or melt of the second organic material and maintaining the temperature at a predetermined temperature for a predetermined time. Second between layers of material The organic molecule layer and a step of intercalating.
[0037]
In this case, the amount of the organic substance inserted between the layers of the host inorganic layered substance and the layer interval can be controlled by changing the time during which the host inorganic layered substance is brought into contact with the organic substance solution or melt.
[0038]
In particular, when two-stage intercalation is performed using a first organic material and a second organic material, these first organic material and second organic material are functional groups that are the same or similar in structure to each other. Have These functional groups are, for example, at least one functional group selected from the group consisting of an amino group, an alkyl group, an anil group, a sulfone group, a cyano group, and a carbonyl group.
[0039]
In the present invention, when intercalation between the layers of the host inorganic layered material is performed, the reaction time is generally preferably 1 hour or more and 1 month or less. This is because if the reaction time is shorter than 1 hour, the intercalation reaction is not sufficient, and the inconvenience that the layer spacing does not become constant tends to occur. On the other hand, the intercalation reaction reaches equilibrium and the layer spacing is constant. This is because it only takes a month. The reaction time is more preferably 12 hours to 3 days. In many cases, sufficient intercalation is possible with such a reaction time.
[0040]
Moreover, about the temperature in the case of an intercalation, it is set as 0 to 200 degreeC suitably, for example. As for the lower limit temperature, if the temperature is lower than 0 ° C., the inconvenience of water coagulation occurs when an aqueous solution is used. Similarly, when using a liquid consisting only of an organic substance instead of an aqueous solution, inconvenience occurs below the freezing point of the organic substance. About the upper limit temperature, if the temperature is higher than 200 ° C., undesirable reactions such as thermal decomposition and evaporation of organic molecules occur. More preferably, the temperature is set to room temperature (20 ° C.) or higher and 150 ° C. or lower. This is disadvantageous in that if the temperature is lower than room temperature (20 ° C.), the intercalation reaction does not proceed rapidly (slow). On the other hand, if the temperature is higher than 150 ° C., it is not preferable such as thermal decomposition or vaporization of organic molecules. This is because the possibility of reaction occurring is increased.
[0041]
Furthermore, the composition of the inorganic-organic composite material is preferably a host inorganic layered material (for example, HTiNbO_Five) The total amount of the guest organic material is 0.01 mol or more and 100 mol or less per mol. This is because if the total amount of the guest organic material is smaller than 0.01 mol, the generated force due to the organic molecular layer becomes small and the driving becomes difficult. On the other hand, when the total amount exceeds 100 mol, the layer spacing of the inorganic layered material becomes small. This is because there is an inconvenience that the shape cannot be maintained due to the enlargement. The total amount of the guest organic material relative to the host inorganic layered material is more preferably 0.1 mol or more and 10 mol or less.
[0042]
In the actuator according to the third aspect of the present invention, the layer interval of the host inorganic layered substance of the inorganic organic composite material is changed by applying an electric field perpendicular to the surface of the inorganic organic composite material as described above. To drive. This actuator has an electrode for applying an electric field in a direction perpendicular to the surface of the host inorganic layered material. Typically, electrodes are provided on one surface and the other surface of the host inorganic layered material, respectively. Yes. This actuator may be constituted by one element part (module or unit), or may be constituted by a combination of a plurality of element parts for obtaining a desired size.
[0043]
The shape of the actuator may be basically any shape, and is designed according to the purpose of use. Specifically, the actuator has a columnar shape (cylindrical shape, prismatic shape, etc.) or a fiber shape with the expansion / contraction direction of the inorganic / organic composite material as an axis, and is preferably a layer of a host inorganic layered substance by applying an electric field. In order to keep the shape when the interval changes or to prevent the liquid crystal from leaking, at least a part of the side surface is coated with a stretchable material, but the coating may be omitted. The actuator is typically composed of a plurality of element parts having a columnar or fiber-like shape with the expansion / contraction direction of the inorganic / organic composite material as an axis, or are connected in series. A plurality of element parts having a structure connected in series have a structure in which a plurality of element parts are connected in parallel (or bundled). In order not to cause any trouble in the expansion and contraction movement, these element parts are integrally coupled by adhesion or the like.
[0044]
The actuator may have a film-like or plate-like shape in which the expansion / contraction direction of the inorganic / organic composite material is perpendicular to the main surface, and preferably maintains its shape when the layer interval of the host inorganic layered substance changes due to electric field application, Alternatively, in order to prevent leakage of the liquid crystal, at least a part of the surface is coated with a stretchable material, but the coating may be omitted. The actuator is typically composed of a plurality of element parts having a film-like or plate-like shape connected in series, or a plurality of element parts having this film-like or plate-like shape are connected in series. The structure has a structure in which a plurality of the above are connected in parallel (or bundled). In order not to cause any trouble in the expansion and contraction movement, these element parts are integrally coupled by adhesion or the like.
The actuator may further be configured by appropriately combining the various shapes as described above according to the purpose of use.
[0045]
The artificial muscle according to the present invention is driven by changing the layer interval of the host inorganic layered material of the inorganic organic composite material by applying an electric field in a direction perpendicular to the surface of the inorganic organic composite material. Others are the same as those of the actuator according to the present invention. This artificial muscle can be applied to an antagonistic muscle configuration, for example. In this case, the artificial muscle is composed of a first artificial muscle and a second artificial muscle, and is configured to perform a stretching operation in which the first artificial muscle and the second artificial muscle share and antagonize each other.
[0046]
The inorganic-organic composite material, actuator, or artificial muscle according to the present invention drives liquid crystal organic molecules existing between layers of an inorganic layered substance by an external electric field, and enables stretching in one direction, that is, in a direction perpendicular to the layer. Is. More specifically, the angle of the organic molecules having liquid crystallinity existing between the layers of the inorganic layered substance with respect to the inorganic layer is changed by an electric field, and the change in the layer interval accompanying the change is taken out as a macro displacement and driven. When such an inorganic-organic composite material is driven by applying an electric field, the change in the layer spacing at the nanometer level is reflected only in the thickness direction (c-axis direction) of the crystal. However, there is an advantage that energy efficiency is increased.
[0047]
Further, this inorganic-organic composite material has a flexible structure because of organic molecules having liquid crystallinity existing between layers. A conventional electrostrictive actuator using an inorganic material has almost no flexibility and a small displacement because the portion to be expanded and contracted is made of ceramics. Therefore, it is a great advantage of the actuator according to the present invention that it has a flexible property while using an inorganic layered substance as a matrix.
[0048]
Thus, the actuator according to the present invention has characteristics superior to those of conventional actuators. In particular, in comparison with the conventional liquid crystal actuator, since the inorganic substance is used as a skeleton, the strength durability is excellent, and since it has a layered structure, response speed and energy conversion efficiency are improved by utilizing the anisotropy. Furthermore, in comparison with the conventional inorganic actuator, it has the characteristics that it has flexibility and a large displacement can be obtained.
[0049]
The drive mechanism of the inorganic-organic composite material according to the present invention will be described in more detail with reference to FIG. FIG. 1 is a schematic diagram showing the structure of an inorganic organic composite material (intercalation compound) according to the present invention in which liquid crystal is held between layers of a layered inorganic skeleton of a layered inorganic substance before and after applying a voltage.
[0050]
When an organic substance is intercalated into an inorganic layered substance, generally, organic molecules are present between the layers in a state of being oriented at a certain angle with respect to the inorganic layer. This corresponds to FIG. 1A when no voltage is applied. When liquid crystal molecules are intercalated between layers, the liquid crystal layer cooperatively attempts to align the molecules with respect to the electric field by applying a voltage. When the dielectric anisotropy of liquid crystal molecules is positive, as shown in FIG. 1B, the liquid crystal molecules are aligned so that the major axis direction is parallel to the direction of the electric field, and at this time, the layer spacing increases. On the other hand, when the dielectric anisotropy of the liquid crystal molecules is negative, as shown in FIG. 1C, the liquid crystal molecules are aligned so that the major axis direction approaches the direction of the electric field, and the layer spacing is reduced at this time. .
[0051]
This change in the layer spacing is a nanometer level minute, but this displacement reaches several to several tens of percent of the original layer spacing. When the entire crystal of the inorganic-organic composite material is observed, its c-axis direction A huge displacement occurs in the (thickness direction). As described above, there is an electrostrictive element such as PZT as an actuator using an inorganic substance, but the displacement is about 0.1%, and the actuator using the inorganic-organic composite material according to the present invention is far more than that. Displacement greater than.
[0052]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings of the embodiments, the same or corresponding parts are denoted by the same reference numerals.
[0053]
First, a first embodiment of the present invention will be described. In this first embodiment, KTiNbO as an inorganic layered material._FiveAn inorganic-organic composite material in which liquid crystal is intercalated between the layers, a manufacturing method thereof, and displacement upon application of voltage to the inorganic-organic composite material will be described.
[0054]
FIG. 2 shows the structure of this inorganic-organic composite material when no voltage is applied. As shown in FIG. 2, this inorganic-organic composite material is composed of KTiNbO as an inorganic layered substance._Five5CB layers 15 and 16 as molecular layers exhibiting liquid crystallinity are inserted between the inorganic layers 11 and 12 through butylamine layers 13 and 14 as organic molecular layers. Here, the butylamine layers 13 and 14 and the 5CB layers 15 and 16 have molecular orientation that is in a mirror image relationship with respect to the bisector of the space between the inorganic layers 11 and 12. Butylamine layers 13 and 14 are NH_Three ⁺The sides are bonded to the inorganic layers 12 and 13, respectively. The 5CB layers 15 and 16 are oriented so that their CN groups face each other.
[0055]
Next, the manufacturing method of this inorganic organic composite material is demonstrated.
This inorganic-organic composite material is KTiNbO_FivePreparation of single crystal, this KTiNbO_FiveHTiNbO by single crystal processing_FivePreparation of single crystal and this HTiNbO_FiveIt is manufactured through a two-step intercalation process for a single crystal. Hereinafter, these steps will be described in detail.
[0056]
KTiNbO _Five Single crystal production
First, KTiNbO_FiveThe powder is put into a platinum crucible, and this platinum crucible is kept at 1400 ° C. in the atmosphere for 5 hours, then gradually cooled to 1150 ° C. at a cooling rate of 10 ° C./h, and further cooled to room temperature to obtain a molded body. Next, this molded body is fired. As a firing method, a double crucible method was adopted in which the molded body was placed in a platinum crucible having a volume of 20 ml, and this platinum crucible was placed in an alumina crucible that was one size larger and sealed with an alumina lid. The melted solidified body obtained by this firing was taken out from the platinum crucible, and a clean transparent single crystal piece was selected. KTiNbO_FiveThe shape of the crystal is generally a plate shape reflecting the anisotropy of the crystal structure. When a single crystal is taken out by mechanical operation, the maximum (2-3) mm × (2-3) The thing of a magnitude | size about mm x (1-2) mm is obtained. KTiNbO_FiveThe crystal structure of is shown in FIG.
[0057]
This KTiNbO_FiveThe X-ray diffraction pattern of the single crystal is shown in FIG. FIG. 4 shows that only the (001) diffraction peak is seen, and the sample measurement surface is the c-plane. The interplanar spacing calculated from the (002) diffraction peak in the figure was 0.900 nm (9.00 mm). This KTiNbO by EDX_FiveWhen the composition of the single crystal was quantitatively analyzed, the metal composition ratio was K: Ti: Nb = 0.97: 1: 0.98.
[0058]
HTiNbO _Five Preparation of single crystal (KTiNbO _Five → HTiNbO _Five )
KTiNbO obtained as described above_FiveThe single crystal was placed in 1N HCl at room temperature and allowed to stand for 2 weeks. By this treatment, KTiNbO_FiveK ions in the single crystal are exchanged for H ions, and HTiNbO_FiveA single crystal was obtained. The crystal shape is KTiNbO before ion exchange._FiveThere is almost no change. HTiNbO_FiveThe crystal structure of is shown in FIG.
[0059]
This HTiNbO_FiveThe X-ray diffraction pattern of the single crystal is shown in FIG. The plane spacing calculated from the (002) diffraction peak in the figure is d = 0.848 nm (8.48 cm), and KTiNbO_FiveA slightly smaller value. This HTiNbO by EDX_FiveAs a result of quantitative analysis of the composition of the single crystal, the metal composition ratio was K: Ti: Nb = 0.03: 1: 0.98, and it was found that the K component was almost eliminated. Therefore, this HTiNbO_FiveSingle crystal is KTiNbO_FiveHTiNbO formed by K → H ion exchange while maintaining the crystal structure of_FiveIt is considered to be a single crystal.
[0060]
First stage intercalation: Butylamine-HTiNbO _Five Single crystal production
HTiNbO obtained as described above_FiveN-Butylamine is intercalated into the single crystal. In this intercalation, a 1 mol / l amine solution is prepared using pure water as a solvent, and HTiNbO is prepared._FiveThe reaction was carried out at room temperature for 3 days so that the molar ratio of the amine to the excess was greatly excessive. By this operation, n-butylamine is converted into HTiNbO._FiveIntercalation compound (hereinafter referred to as “butylamine-HTiNbO”)_FiveCrystal) was obtained. This butylamine-HTiNbO_FiveThe X-ray diffraction pattern of the single crystal is shown in FIG. From FIG. 7, only the diffraction peak derived from (001) was observed, and the plane spacing calculated from the (002) diffraction peak was d = 1.721 nm (18.21Å). This butylamine-HTiNbO_FiveThe crystal spacing is HTiNbO._FiveIt is enlarged by about 0.973 nm (9.73 mm) compared with that of, indicating that butylamine was inserted between the layers. When the inclination angle of butylamine existing between the inorganic layers is estimated with reference to FIG. 8, HTiNbO_FiveCrystal layer spacing d₁= 0.848 nm (8.48 mm), butylamine-HTiNbO_FiveCrystal layer spacing d = 1.721 nm (18.21 Å), n-butylamine molecular length a = 0.616 nm (6.16 Å), Δd = d−d₁= 0.973 nm (9.73 Å), it is estimated that the inclination angle θ = arcsin (Δd / 2a) = arcsin (0.973 / 2 × 0.616) = 52 °.
[0061]
Next, this butylamine-HTiNbO_FiveIn order to clarify the composition of the single crystal, quantitative analysis of nitrogen was performed by the oxygen circulation TCD method. Since one nitrogen atom exists in one molecule of butylamine, the composition of the intercalation compound including the organic molecule can be determined by performing a quantitative analysis of nitrogen. The composition formula obtained from the measurement results is
(Butylamine)_0.56HTiNbO_Five
Met.
[0062]
Second stage intercalation: 5CB-butylamine-HTiNbO _Five Single crystal production
Butylamine-HTiNbO obtained by first stage intercalation as described above_FiveSecond stage intercalation is performed on the single crystal. Insert material is room temperature nematic liquid crystal 5CB (4-aminobutoxy cyanobiphenyl: C_FiveH₁₁(C₆H_Four)₂CN), which is a nematic phase in the range of 22 ° C to 35 ° C. First, butylamine-HTiNbO_FiveSeveral single crystals were placed in a glass sample tube, and 5CB (Merck, model number K-15) was poured in an amount sufficient to immerse them in the sample tube. Thereafter, the sealed sample tube was put in an oven, and heat treatment was performed at 130 ° C. for 12 to 60 hours.
[0063]
Butylamine-HTiNbO_FiveA sample obtained by heat treating a single crystal together with 5CB at 130 ° C. for 24 hours (hereinafter referred to as “5CB-butylamine-HTiNbO”_FiveFIG. 9 shows the X-ray diffraction pattern. From FIG. 9, only the diffraction peak derived from (001) was observed, and the layer interval calculated from the (002) diffraction peak was d = 3.994 nm (39.94 cm). This is butylamine-HTiNbO_FiveCompared to the above, it is greatly enlarged to about 2.173 nm (21.73 mm), and it can be considered that 5CB was inserted between the layers. This change in the layer spacing is sufficiently larger than the molecular length of 1.539 nm (16.39 mm) of 5CB (calculated by MOPAC), and the inclination angle of butylamine with respect to the inorganic layer intercalated in the first stage intercalation Is invariable, two or more molecular layers are inserted between the layers. Assuming that the tilt angle of butylamine is unchanged and that there are two molecular layers of 5CB, the tilt angle of 5CB is estimated with reference to FIG. 10, and butylamine-HTiNbO_FiveSingle crystal layer spacing d₁= 1.821 nm (18.21 mm), 5CB-butylamine-HTiNbO_FiveCrystal layer spacing d = 3.994 nm (39.94Å) (heat treatment condition 130 ° C., 24 hours), 5CB molecular length a = 1.539 nm (16.39Å), Δd = d−d₁Since it is = 2.173 nm (21.73 mm), it is estimated that the inclination angle θ = arcsin (Δd / 2a) = arcsin (2.173 / 2 × 1.639) = 42 °.
[0064]
FIG. 11 shows butylamine-HTiNbO._FiveThe relationship between reaction time and layer spacing when 5CB is inserted between the layers is shown. However, the reaction temperature was 130 ° C. From FIG. 11, the layer spacing increases with the increase in reaction time. From this, it can be seen that as the heat treatment time increases, a large amount of 5CB is inserted between the layers, and the layer spacing increases.
[0065]
Butylamine-HTiNbO_FiveInfrared (IR) measurement was performed to further confirm that 5CB was inserted into the. FIG. 12 shows 5CB-butylamine-HTiNbO._FiveThe IR spectrum of a single crystal (heat treatment condition 130 ° C., 24 hours) is shown. In this system, it is easy to confirm that 5CB has been inserted. This is 2200cm for 5CB^-1There is a clear peak derived from the stretching vibration of the nearby cyano group (C≡N), but butylamine-HTiNbO_FiveBecause there is no such thing. FIG. 12 clearly shows that a peak derived from a cyano group is present, so that 5CB is inserted.
[0066]
Next, this 5CB-butylamine-HTiNbO_FiveConsider the displacement when an electric field is applied to the crystal. Since 5CB is a liquid crystal having positive dielectric anisotropy, when an electric field is applied, the major axis of the molecule is aligned so as to be parallel to the electric field vector. In the initial state where no electric field is applied, when the inclination angle of 5CB molecules relative to the inorganic layer is 42 °, when the inclination angle changes to 90 ° by application of the electric field, the increase in the layer spacing is 2.2 nm (22 cm). Therefore, in this crystal, an extremely large extension of 54% at the maximum in the c-axis direction can be obtained as compared to before application of the electric field.
[0067]
Next explained is the second embodiment of the invention. In the second embodiment, 4-aminobutoxy-4′-cyanobiphenyl (hereinafter referred to as “aminobioxy-4′-cyanobiphenyl”) is used instead of n-butylamine used as the guest organic substance in the first embodiment. Called ABCB).
[0068]
The structure of the inorganic-organic composite material according to the second embodiment when no voltage is applied corresponds to a structure in which the butylamine layer in FIG. 2 is replaced with an ABCB layer.
[0069]
Next, the manufacturing method of this inorganic organic composite material is demonstrated.
This inorganic-organic composite material is KTiNbO_FiveSingle crystal fabrication, KTiNbO_FiveHTiNbO by single crystal processing_FiveSingle crystal fabrication and HTiNbO_FiveManufactured through a two-step intercalation process for a single crystal, KTiNbO_FiveFrom single crystal production to HTiNbO_FiveSince the process up to the production of the single crystal is the same as that of the first embodiment, the description thereof is omitted, and HTiNbO is omitted._FiveOnly the two-stage intercalation process for a single crystal will be described.
[0070]
First stage intercalation: ABCB-HTiNbO _Five Single crystal production
The synthesis of ABCB used in the first stage intercalation was performed with reference to the method reported by Kawasumi et al. (Mol. Cryst. Liq. Cryst., 281 (1996) 91.). The obtained ABCB was mixed with a water / ethanol mixed solvent (H₂O: C₂H_FiveIt was dissolved in OH = 1: 1) to prepare a 0.1 mol / l ABCB solution. This solution is put into a sample tube and ABCB: HTiNbO is added to this._FiveThe HTiNbO crystal was added so that = 10: 1. The size of each crystal was 1 to 2 mm square, and the thickness was about 0.1 to 0.5 mm. The sample tube was sealed, placed in an oven, and heat-treated at 70 ° C. for 12 hours.
[0071]
By this operation, ABCB becomes HTiNbO._FiveIntercalation compound (hereinafter referred to as “ABCB-HTiNbO”_FiveCrystal) was obtained. This ABCB-HTiNbO_FiveThe X-ray diffraction pattern of the single crystal is shown in FIG. As shown in FIG. 13, a diffraction peak derived from (001) was observed, and the interplanar spacing calculated from the (002) diffraction peak was d = 3.293 nm (32.93 Å). This is HTiNbO_Five2.45 nm (24.45 cm) is larger than that of ABCB, and it can be considered that ABCB was inserted between the layers. Assuming that the ABCB molecule inserted between the layers forms a bimolecular layer between the inorganic layers, the molecular length of ABCB is 1.682 nm (16.82 cm) (calculated by MOPAC). The tilt angle for the layer is arcsin^-1It is estimated that (2.445 / (2 × 1.682)) = 47 °.
[0072]
Next, ABCB-HTiNbO_FiveQuantitative analysis of nitrogen was performed to clarify the composition. The resulting composition formula is
(ABCB)_0.62HTiNbO_Five
Met.
[0073]
Second stage intercalation: 5CB-ABCB-HTiNbO _Five Single crystal production
ABCB-HTiNbO with first stage intercalation_FiveSingle crystal was second stage intercalated. The insertion material is room temperature nematic liquid crystal 5CB which is the same as that used in the first embodiment.
[0074]
ABCB-HTiNbO_FiveA sample obtained by heat-treating a single crystal together with 5CB at 130 ° C. for 12 hours (hereinafter referred to as “5CB-ABCB-HTiNbO”)._FiveFIG. 14 shows an X-ray diffraction pattern. From the X-ray diffraction pattern of the same figure, a (001) diffraction peak was observed, and the layer spacing calculated from the (002) diffraction peak was d = 3.855 nm (38.55Å). This is ABCB-HTiNbO_FiveIt is enlarged by about 0.562 nm (5.62 cm) compared with the above, and it can be considered that 5CB was inserted between the layers. Since the change in the layer spacing is considerably smaller than the molecular length of 5CB (1.639 nm (16.39 cm)), the inserted 5CB is expected to form a single molecular layer. Assuming that the 5CB between the layers forms a monolayer and that the tilt angle of ABCB is unchanged, the tilt angle of 5CB inserted between the layers by the second stage intercalation process is arcsin.^-1It is estimated that (0.562 / 1.639) = 20 °.
[0075]
FIG. 15 shows ABCB-HTiNbO._FiveThe relationship between reaction time and layer spacing when 5CB is inserted between the layers is shown. FIG. 15 shows that the layer spacing tends to increase depending on the reaction time. From this, it can be seen that as the reaction time increases, 5CB is inserted in a large amount between the layers, and the layer spacing increases.
Next, this 5CB-ABCB-HTiNbO_FiveConsider the displacement when an electric field is applied to a single crystal. Assuming that the 5CB molecular tilt angle with respect to the inorganic layer is 20 ° in the initial state where no electric field is applied when 5CB is contained between the layers, if the tilt angle changes to 90 ° by the application of the electric field, the layer spacing The increase of 1.077 nm (10.77 mm) is 28%.
[0076]
Next explained is the third embodiment of the invention. In the third embodiment, an actuator using an inorganic / organic composite material (intercalation compound) according to the present invention will be described.
[0077]
FIG. 16 shows a basic unit of the actuator according to the third embodiment.
The inorganic-organic composite material (intercalation compound) used in this actuator may be that of the first embodiment or the second embodiment, or liquid crystal molecules other than 5CB or HTiNbO._FiveThose using other inorganic layered materials may be selected as necessary. In this actuator, electrodes 22 and 23 are provided on both upper and lower surfaces of a columnar inorganic organic composite material 21 such as a cylinder or a rectangular parallelepiped, and lead wires 24 and 25 are taken out from these electrodes 22 and 23, respectively. The inorganic-organic composite material 21 preferably has a bulk crystal, thin film, or thick film shape that is highly oriented in the c-axis direction so that a large displacement can be efficiently obtained. Is a single crystal, a high c-axis oriented polycrystal, a high c-axis oriented thin film, and the like. The outer peripheral surfaces of the inorganic organic composite material 21 and the electrodes 22 and 23 prevent leakage of liquid crystal molecules existing between the inorganic layers of the inorganic organic composite material 21 and separation of the inorganic layer accompanying expansion and contraction of the inorganic organic composite material 21. In order to maintain the shape, a coating 26 made of an organic polymer is applied. The material of the coating 26 made of organic polymer is basically any material as long as it has excellent durability and has elasticity and flexibility so as not to become a burden when driving the inorganic-organic composite material. Specifically, for example, silicone rubber, fluororubber, chloroprene rubber and the like are used.
[0078]
FIG. 17 shows a laminated actuator according to a fourth embodiment of the present invention. As shown in FIG. 17, this laminated actuator is obtained by laminating a plurality of basic units of the actuator shown in FIG. 16 in the c-axis direction, which is the expansion / contraction direction, so that sufficient displacement can be obtained. Here, it is important that a plurality of actuators are laminated in the extending and contracting direction, and the overall shape of the laminated actuator may be an arbitrary shape such as a rectangular parallelepiped or a cylinder. Although FIG. 17 shows a case where the number of basic units is 4, the number of basic units is selected as necessary. A voltage is applied to the actuator of each unit from the outside through lead wires 24 and 25.
[0079]
FIG. 18 shows a fibrous actuator according to a fifth embodiment of the present invention. As shown in FIG. 18, this fibrous actuator is based on a structure in which the number of stages of the laminated actuator shown in FIG. 17 is sufficiently increased to form a fibrous form as a whole, and a plurality of them are bundled in parallel. is there.
[0080]
According to the fifth embodiment, since the actuator is configured by bundling a plurality of fibrous laminated actuators in parallel, the generation force and strength of the actuator can be dramatically increased. Further, each fiber of this actuator is flexible and is driven cooperatively by applying a voltage, so that it is suitable as an actuator imitating the muscles of a living organism.
[0081]
According to the third, fourth, and fifth embodiments described above, a high-performance actuator having characteristics such as flexibility, high-speed response, and large displacement is realized, which is suitable for fields such as robotics and medicine. Can be used.
Here, when the actuators according to the third, fourth, and fifth embodiments are compared with the displacement elements disclosed in Japanese Patent Laid-Open Nos. 05-110153 and 06-125120, there are many as follows. Has the advantage of
(1) Although the element disclosed in the above publication is an all solid type, the actuators according to the third, fourth, and fifth embodiments are not all solid because the liquid crystal is inserted between the layers of the inorganic layered material. This is the biggest difference. Since compounding with liquid crystal gives the element flexibility, an artificial element that requires flexible characteristics such as biological muscles can be obtained. This is a great advantage in the development of autonomous robots that have developed in recent years.
(2) In the device disclosed in the above publication, the intercalation reaction is performed only in one stage in the embodiment. On the other hand, in the actuators according to the third, fourth and fifth embodiments, two or more stages of intercalation are performed when manufacturing the inorganic-organic composite material constituting the actuator. According to this method, it is possible to obtain advantages such as that most liquid crystal molecules can be inserted and that the amount of liquid crystal molecules inserted can be easily controlled by the insertion temperature and time.
(3) In the device disclosed in the above publication, the powder of the intercalation substance is used in the examples, but this cannot sufficiently utilize the anisotropy peculiar to the intercalation substance. On the other hand, the actuators according to the third, fourth and fifth embodiments use a single crystal which is an optimum matrix for obtaining displacement.
[0082]
FIG. 19 shows a drive system according to a sixth embodiment of the present invention. This drive system is an artificial antagonist muscle drive system.
As shown in FIG. 19, this drive system is a combination of two artificial muscles 61 and 62. As these artificial muscles 61 and 62, for example, an actuator similar to that of the fifth embodiment can be used. The artificial muscle 61 is stored in a container 63, and the transmission rods 64 at both ends of the artificial muscle 61 are drawn out of the container 63. Similarly, the artificial muscle 62 is housed in the container 65, and the transmission rods 66 at both ends of the artificial muscle 62 are drawn out of the container 65. The transmission rods 64 and 66 at one end of the artificial muscles 61 and 62 are connected to the column 67. Similarly, the transmission rods 64 and 66 at the other ends of the artificial muscles 61 and 62 are connected to the support column 68. These struts 67 and 68 are coupled to each other through a joint 69 and can rotate around the joint 69.
[0083]
In the sixth embodiment, the artificial muscles 61 and 62 are antagonized with respect to the pillars 67 and 68 that hit the bones of the organism. That is, a similar operation to the antagonistic muscle can be performed by the cooperative operation of the artificial muscles 61 and 62. For example, the lengths of the artificial muscles 61 and 62 when no voltage is applied are all equal to L, and the voltage V between the electrodes of each actuator constituting them is equal.₁In the state shown in FIG. 19, the artificial muscle 61 is contracted when the length of the artificial muscles 61 and 62 is L + ΔL / 2, for example, when the extension amount when Δ is applied is ΔL. In contrast, the artificial muscle 62 extends in the opposite direction. In this case, the voltage V applied between the electrodes of each actuator constituting the artificial muscle 61.₂Is 0 <V₂<V₁The voltage V applied between the electrodes of each actuator constituting the artificial muscle 62_ThreeIs V₁<V_ThreeIt is.
[0084]
According to the fifth embodiment, the same advantages as in the third, fourth or fifth embodiment can be obtained, and the two artificial muscles 61 and 62 are combined to constitute an antagonistic muscle. Thus, an advantage can be obtained in that a balanced movement can be achieved as compared with the case where the artificial muscle is driven alone.
[0085]
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, The various deformation | transformation based on the technical idea of this invention is possible.
[0086]
For example, the numerical values, materials, structures, shapes, processes, and the like given in the above-described embodiments are merely examples, and different numerical values, materials, structures, shapes, processes, and the like may be used as necessary.
[0087]
【The invention's effect】
As described above, according to the present invention, in an inorganic-organic composite material comprising a host inorganic layered substance and at least one kind of guest organic substance present between the host inorganic layered substance, at least one kind of guest organic Inorganic organic composite material that has satisfactory performance in terms of toughness, flexibility, magnitude of displacement obtained, response speed, energy efficiency in taking out displacement, etc., by including organic molecules having liquid crystallinity Actuators and artificial muscles can be realized. These inorganic-organic composite materials, actuators, and artificial muscles can be easily manufactured by an intercalation technique.
[Brief description of the drawings]
FIG. 1 is a schematic diagram for explaining a driving mechanism by applying a voltage of an inorganic-organic composite material according to the present invention in which a liquid crystal is inserted between layers of an inorganic layered substance.
FIG. 2 is a schematic diagram showing a crystal structure of an inorganic-organic composite material according to the first embodiment of the present invention.
FIG. 3 KTiNbO_FiveIt is a basic diagram which shows the crystal structure of this.
FIG. 4 shows KTiNbO produced in the first embodiment of the present invention._FiveIt is a basic diagram which shows the X-ray-diffraction pattern of a crystal | crystallization.
FIG. 5: HTiNbO_FiveIt is a basic diagram which shows the crystal structure of this.
FIG. 6 shows an HTiNbO fabricated in the first embodiment of the present invention._FiveIt is a basic diagram which shows the X-ray-diffraction pattern of a crystal | crystallization.
FIG. 7 shows butylamine-HTiNbO produced in the first embodiment of the present invention._FiveIt is a basic diagram which shows the X-ray-diffraction pattern of a crystal | crystallization.
FIG. 8 shows butylamine-HTiNbO produced in the first embodiment of the present invention._FiveIt is a basic diagram for estimating the inclination angle of butylamine between crystal layers.
FIG. 9 shows 5CB-butylamine-HTiNbO prepared in the first embodiment of the present invention._FiveIt is a basic diagram which shows the X-ray-diffraction pattern of a crystal | crystallization.
FIG. 10 shows 5CB-butylamine-HTiNbO prepared in the first embodiment of the present invention._FiveIt is a basic diagram for estimating the inclination angle of 5CB between crystal | crystallization layers.
FIG. 11 shows 5CB-butylamine-HTiNbO prepared in the first embodiment of the present invention._FiveIt is a basic diagram which shows the relationship between the layer interval of a crystal | crystallization, and reaction time.
FIG. 12 shows 5CB-butylamine-HTiNbO prepared in the first embodiment of the present invention._FiveIt is a basic diagram which shows the infrared spectrum of a crystal | crystallization.
FIG. 13 shows ABCB-HTiNbO fabricated in the second embodiment of the present invention._FiveIt is a basic diagram which shows the X-ray-diffraction pattern of a crystal | crystallization.
FIG. 14 shows 5CB-ABCB-HTiNbO fabricated in the second embodiment of the present invention._FiveIt is a basic diagram which shows the X-ray-diffraction pattern of a crystal | crystallization.
FIG. 15 shows 5CB-ABCB-HTiNbO fabricated in the second embodiment of the present invention._FiveIt is a basic diagram which shows the relationship between the layer interval of a crystal | crystallization, and reaction time.
FIG. 16 is a sectional view showing an actuator according to a third embodiment of the present invention.
FIG. 17 is a cross-sectional view showing a multilayer actuator according to a fourth embodiment of the invention.
FIG. 18 is a schematic diagram showing a fibrous actuator according to a fifth embodiment of the present invention.
FIG. 19 is a sectional view showing a drive system according to a sixth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11, 12 ... Inorganic layer, 13, 14 ... Butylamine layer, 15, 16 ... 5CB layer, 21 ... Inorganic organic composite material, 22, 23 ... Electrode, 24, 25 ... Lead wire, 26 ... coating with organic polymer, 61, 62 ... artificial muscle

Claims (6)

intercalating a pair of organic molecular layers composed of n-butylamine or 4-aminobutoxy-4′-cyanobiphenyl between layers of a host inorganic layered material composed of an HTiNbO ₅ single crystal ;
Intercalating the pair of organic molecular layers between the layers of the host inorganic layered material, and then intercalating at least one organic molecular layer comprising the room temperature nematic liquid crystal 5CB between the layers of the host inorganic layered material. A method for producing an inorganic-organic composite material. The host inorganic layered material is brought into contact with a solution or melt of n-butylamine or 4-aminobutoxy-4′-cyanobiphenyl and held at a predetermined temperature for a predetermined time, whereby the pair of host inorganic layered materials is interposed between the host inorganic layered materials. The organic inorganic layer is intercalated, and the host inorganic layered material is brought into contact with the solution or melt of room temperature nematic liquid crystal 5CB and held at a predetermined temperature for a predetermined time, so that the room temperature layer is interposed between the host inorganic layered materials. The method for producing an inorganic-organic composite material according to claim 1, wherein at least one organic molecular layer composed of the nematic liquid crystal 5CB is intercalated. A pair of organic molecular layers composed of n-butylamine or 4-aminobutoxy-4'-cyanobiphenyl is converted into HTiNbO. _Five Intercalating between layers of a host inorganic layered material made of a single crystal;
Intercalating the pair of organic molecular layers between the layers of the host inorganic layered material, and then intercalating at least one organic molecular layer comprising the room temperature nematic liquid crystal 5CB between the layers of the host inorganic layered material. Actuator manufacturing method. The host inorganic layered material is brought into contact with a solution or melt of n-butylamine or 4-aminobutoxy-4′-cyanobiphenyl and held at a predetermined temperature for a predetermined time, whereby the pair of host inorganic layered materials is interposed between the host inorganic layered materials. The organic inorganic layer is intercalated, and the host inorganic layered material is brought into contact with the solution or melt of room temperature nematic liquid crystal 5CB and held at a predetermined temperature for a predetermined time, so that the room temperature layer is interposed between the host inorganic layered materials. 4. The method of manufacturing an actuator according to claim 3, wherein at least one organic molecular layer composed of the nematic liquid crystal 5CB is intercalated. A pair of organic molecular layers composed of n-butylamine or 4-aminobutoxy-4'-cyanobiphenyl is converted into HTiNbO. _Five Intercalating between layers of a host inorganic layered material made of a single crystal;
Intercalating the pair of organic molecular layers between the layers of the host inorganic layered material, and then intercalating at least one organic molecular layer comprising the room temperature nematic liquid crystal 5CB between the layers of the host inorganic layered material. Artificial muscle manufacturing method. The host inorganic layered material is brought into contact with a solution or melt of n-butylamine or 4-aminobutoxy-4′-cyanobiphenyl and held at a predetermined temperature for a predetermined time, whereby the pair of host inorganic layered materials is interposed between the host inorganic layered materials. The organic inorganic layer is intercalated, and the host inorganic layered material is brought into contact with the solution or melt of room temperature nematic liquid crystal 5CB and held at a predetermined temperature for a predetermined time, so that the room temperature layer is interposed between the host inorganic layered materials. The method for producing an artificial muscle according to claim 5, wherein at least one organic molecular layer composed of the nematic liquid crystal 5CB is intercalated.

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