200824914 ⑴ . 九、發明說明 • 【發明所屬之技術領域] 本發明關於熱彎曲致動器，其已被發展主要用於提供 改良的噴墨噴嘴，該噴嘴藉由熱彎曲致動而噴射墨水。 【先前技術】 本申請案先前已插述使用熱彎曲致動之微電機機械 _ (MEMS)噴嘴的過多現象。熱彎曲致動一般意指由具有電 流通過的一材料之熱膨脹所產生相對於另一材料的彎曲運 動。所產生的彎曲運動可用於選擇性地藉由葉片或輪葉的 運動而從噴嘴開口噴射墨水。該葉片或輪葉在噴嘴腔室內 產生壓力波。 熱彎曲噴墨噴嘴的一些代表性類型，例示在上文交叉 參考段所列之專利案或專利申請案中。茲將該等案的內容 倂入做參考。 φ 申請人的美國第US 6410167專利案描述的噴墨噴嘴 ’具有位於噴嘴腔室內的葉片和位於噴嘴腔室外部的熱彎 曲致動器。致動器採用傳導性材料（例如氮化鈦）之下主動 樑的形式，其熔合至非傳導性材料（例如二氧化矽）之上被 動樑。藉由容置穿過噴嘴腔室之壁中的槽，致動器連接至 臂。當電流經過下主動樑時，致動器向上彎曲，結果葉片 向界定在噴嘴腔室之頂部的噴嘴開口運動，藉此噴射墨水 液滴。此設計的優點是其結構的簡單性，此設計的缺點是 葉片的兩個面對抗噴嘴腔室內側之相對黏性的墨水工作。 -4 - 200824914 (2) • 申請人的美國第US 6260953號專利案（讓與給本案的 . 申請人）描述的噴墨噴嘴，其中的致動器形成噴嘴腔室的 運動頂部。致動器採用聚合物材料包覆傳導性材料之蛇形 (serpeiitiiie)芯部的形式。當致動時，致動器朝噴嘴腔室 的底板彎曲，增加腔室內的壓力，並迫使墨水液滴從界定 在腔室頂部內的噴嘴開口流出。噴嘴開口界定在頂部之非 運動部份。此設計的優點是運動頂部只有一個面須對抗噴 嘴腔室內側之相對黏性的墨水工作，此設計的缺點是以聚 ^ 合物材料包覆蛇形傳導性元件之致動器的結構，在微電機 機械方法中難以獲得。 申請人的美國第US 6623 1 0 1號專利案描述的噴墨噴 嘴包含有噴嘴腔室，其可動頂部具有界定在其內的噴嘴開 口。該可動頂部藉由臂連接至位在噴嘴腔室外部的熱彎曲 致動器。致動器採取上主動樑和下被動樑相隔開的形式。 藉由將主動樑和被動樑相隔開，熱彎曲效率最大化，因爲 φ 被動樑不能做爲主動樑的散熱器。當電流通過上主動樑時 ，具有噴嘴開口界定在其內的可動頂部被朝噴嘴腔室的底 板轉動，藉此噴射經過噴嘴開口。因爲噴嘴開口隨著頂部 運動，所以藉由適當地修飾噴嘴邊緣的形狀，可控制液滴 移動的方向。此設計的優點是運動頂部只有一個面必須對 抗噴嘴腔室內側相對黏性的墨水工作。另一優點是藉由相 隔開的主動和被動樑構件，可將熱損失最小化。此設計的 缺點是相隔開的主動和被動樑構件喪失構造上的剛性。 因此需要改善熱彎曲噴墨噴嘴的設計，以獲得更有效 -5- 200824914 (3) ^ 率的液滴噴射和改善的機械堅固性。 【發明內容】 本發明的第一方面提供一種噴墨噴嘴組合體，包含： 一噴嘴腔室，包括底部和頂部，該頂部具有界定在其中的 噴嘴開口，該頂部具有可朝該底部運動的運動部；和一熱 彎曲致動器，具有複數懸臂樑，用以將墨水噴射經過該噴 0 嘴開口。該致動器包括：一第一主動樑，用以連接至驅動 fe路，和一'桌一^被動棟’機械式地連動該第一探，使得當 電流通過該第一樑時，該第一樑相對於該第二樑膨脹，導 致該致動器彎曲。其中該運動部包含該致動器。 選擇性地，該第一主動樑界定該頂部之全部面積的至 少 3 0% 。 選擇性地，該第一主動樑界定該頂部之至少部份外表 面。 φ 選擇性地，該噴嘴開口被界定在該運動部內，使得該 噴嘴開口可相對於該底部運動。 選擇性地，該致動器可相對於該噴嘴開口運動。 選擇性地，扭曲樑元件界定該第一樑，該扭曲樑元件 具有複數的接觸樑構件。 選擇性地，該複數的接觸樑構件包含複數較長的樑構 件和至少一較短的樑構件，該複數較長的樑構件沿著該第 一樑的縱軸線延伸，該較短的樑構件橫越該第一樑的橫軸 線延伸，且互連較長的樑構件。 -6 - 200824914 (4) 胃 選擇性地，該複數樑其中之一包含多孔材料。 . 選擇性地，該多孔材料是具有介電常數2或更少之多 孔二氧化砍。 選擇性地，該熱彎曲致動器更包含介於該第一樑和該 第二樑之間的第三絕緣樑。 選擇性地，該第三絕緣樑包含多孔材料。 選擇性地，該第一樑熔合或接合至該第二樑。 選擇性地，該第二樑包含多孔材料。 選擇性地，至少部份的該第一樑和該第二樑相隔開。 選擇性地，該第一樑包含的材料是選自包含氮化鈦、 氮化鈦鋁、和鋁合金的群組。 選擇性地，該第一樑包含鋁合金。 選擇性地，該鋁合金包含鋁和具有超過1 〇〇 Gpa楊氏 模數的至少一種其他金屬。 選擇性地，該至少一種金屬是選自包含釩、錳、鉻、 0 銘、和鎳的群組。 選擇性地，該合金包含鋁和釩。 選擇性地，該合金包含至少80%的鋁。 本發明的第二方面提供一種熱彎曲致動器，其具有複 數元件。該致動器包括：一第一主動元件，用以連接至驅 動電路；和一第二被動元件，機械式地連動該第一元件， 使得當電流通過該第一元件時，該第一元件相對於該第二 元件膨脹，導致該致動器彎曲。其中該第一元件包含鋁合 金。 200824914 · (5) ， 選擇性地，該鋁合金包含鋁和具有超過1 〇〇 Gpa楊氏 ^ 模數的至少一種其他金屬。 選擇性地，該至少一種金屬是選自包含釩、錳、鉻、 鈷、和鎳的群組。 選擇性地，該合金包含鋁和釩。 選擇性地，該合金包含至少80%的鋁。 選擇性地，該第一和第二元件是懸臂樑。 選擇性地，該第一樑沿著其縱軸線熔合或接合至該第 • 二樑。 選擇性地，至少部份的該第一樑和該第二樑相隔開， 藉此將第一樑和部份的第二樑絕緣。 選擇性地，該複數元件其中之一包含多孔材料。 選擇性地，該多孔材料是具有約爲2或更少的介電常 數。 選擇性地，第三絕緣樑介於該第一樑和該第二樑之間 選擇性地，該第三絕緣樑包含多孔材料。 選擇性地，該第二樑包含多孔材料。 本發明的另一方面提供一種噴墨噴嘴組合體，包含： 一噴嘴腔室，具有噴嘴開口和墨水入口；和一熱彎曲致動 器，具有複數懸臂樑，用以將墨水噴射經過該噴嘴開口。 該致動器包括：一第一主動樑，用以連接至驅動電路；和 一第二被動樑，機械式地連動該第一樑，使得當電流通過 該第一樑時，該第一樑相對於該第二樑膨脹，導致該致動 -8 - 200824914 (6) ' 器彎曲。其中該第一樑包含鋁合金。 - 選擇性地，該噴嘴腔室包括底部和具有運動部的頂部 ，藉此，該致動器的致動將該運動部朝該底部運動。 選擇性地，該運動部包含致動器。 選擇性地，該第一主動樑界定該頂部之全部面積的至 少 3 0 % 。 選擇性地，該第一主動樑界定該噴嘴腔室之至少部份 外表面。 選擇性地，該噴嘴開口被界定在該運動部內，使得該 噴嘴開口可相對於該底部運動。 本發明的第三方面提供一種熱彎曲致動器，其具有複 數元件。該致動器包括：一第一主動元件，用以連接至驅 動電路；和一第二被動元件，機械式地連動該第一元件， 使得當電流通過該第一元件時，該第一元件相對於該第二 元件膨脹，導致該致動器彎曲。其中該複數元件其中之一 0 包含多孔材料。 選擇性地，該多孔材料是具有約爲2或更少的介電常 數。 選擇性地，該多孔材料是多孔二氧化矽。 選擇性地，該第一和第二樑是懸臂樑。 在另一方面提供一種熱彎曲致動器，其更包含介於該 第一樑和該第二樑之間的第三絕緣樑。 選擇性地，該第三絕緣樑包含多孔材料。 選擇性地，該第一樑沿著其縱軸線熔合或接合至該第 -9 - 200824914 (7) ^ 二樑。 _ 選擇性地，該第二樑包含多孔材料。 選擇性地，該第一元件包含的材料是選自包含氮化鈦 、氮化鈦鋁、和鋁合金的群組。 選擇性地，該第一樑包含鋁合金。 選擇性地，該鋁合金包含鋁和具有超過〗00 Gpa楊氏 模數的至少一種其他金屬。 選擇性地，該至少一種金屬是選自包含釩、錳、鉻、 鈷、和鎳的群組。 選擇性地，該合金包含鋁和釩。 選擇性地，該合金包含至少80%的鋁。 本發明的另一方面提供一種噴墨噴嘴組合體，包含： 一噴嘴腔室，具有噴嘴開口和墨水入口；和一熱彎曲致動 器，具有複數懸臂樑，用以將墨水噴射經過該噴嘴開口。 該致動器包括：一第一主動樑，用以連接至驅動電路；和 φ 一第二被動樑，機械式地連動該第一樑，使得當電流通過 該第一樑時，該第一樑相對於該第二樑膨脹，導致該致動 器彎曲。其中該複數樑其中之一包含多孔材料。 選擇性地，該噴嘴腔室包括底部和具有運動部的頂部 ，藉此，該致動器的致動將該運動部朝該底部運動。 選擇性地，該運動部包含致動器。 選擇性地，該第一主動樑界定該頂部之全部面積的至 少 3 0 % 。 選擇性地，該第一主動樑界定該噴嘴腔室之至少部份 -10- 200824914 ⑻ * 外表面。 - 選擇性地，該噴嘴開口被界定在該運動部內’使得該 噴嘴開口可相對於該底部運動。 本發明的第四方面提供一種噴墨噴嘴組合體’包含： 一噴嘴腔室，包括底部和頂部，該頂部具有界定在其中的 噴嘴開口，該頂部具有可朝該底部運動的運動部；和一熱 彎曲致動器，具有複數懸臂樑，用以將墨水噴射經過該噴 嘴開口。該致動器包括：一第一主動樑，用以連接至驅動 電路；和一第二被動樑，機械式地連動該第一樑，使得當 電流通過該第一樑時，該第一樑相對於該第二樑膨脹，導 致該致動器彎曲。 選擇性地，該第一主動樑界定該頂部之全部面積的至 少 3 0 % 。 選擇性地，該第一主動樑界定該頂部之至少部份外表 面。 φ 選擇性地，該噴嘴開口被界定在該運動部內，使得該 噴嘴開口可相對於該底部運動。 選擇性地，該致動器可相對於該噴嘴開口運動。 選擇性地，扭曲樑元件界定該第一樑，該扭曲樑元件 具有複數的接觸樑構件。 選擇性地，該複數的接觸樑構件包含複數較長的樑構 件和至少一較短的樑構件，該複數較長的樑構件沿著該第 一樑的縱軸線延伸’該較短的樑構件橫越該第一機的橫軸 線延伸，且互連較長的樑構件。 -11 - 200824914 ⑼ _ 選擇性地，該複數樑其中之一包含多孔材料。 . 選擇性地，該多孔材料是具有介電常數2或更少之多 孔二氧化矽。 選擇性地，該熱彎曲致動器更包含介於該第一樑和該 第二樑之間的第三絕緣樑。 選擇性地，該第三絕緣樑包含多孔材料。 選擇性地，該第一樑熔合或接合至該第二樑。 選擇性地，該第二樑包含多孔材料。 選擇性地，至少部份的該第一樑和該第二樑相隔開。 選擇性地，該第一樑包含的材料是選自包含氮化鈦、 氮化鈦鋁、和鋁合金的群組。 選擇性地，該第一樑包含鋁合金。 選擇性地，該鋁合金包含鋁和具有超過1 00 Gpa楊氏 模數的至少一種其他金屬。 選擇性地，該至少一種金屬是選自包含釩、錳、鉻、 φ 鈷、和鎳的群組。 選擇性地，該合金包含鋁和釩。 選擇性地，該合金包含至少8 0%的鋁。 本發明的第五方面提供一種噴墨噴嘴組合體，包含： 一噴嘴腔室，包括底部和頂部，該頂部具有界定在其中的 噴嘴開口，該頂部具有可朝該底部運動的運動部；和一熱 彎曲致動器，具有複數懸臂樑，用以將墨水噴射經過該噴 嘴開口。該致動器包括：一第一主動樑，用以連接至驅動 電路；和一第二被動樑，機械式地連動該第一樑，使得當 -12- 200824914 (10) 電流通過該第一樑時，該第一樑相對於該第二樑膨脹，導 致該致動器彎曲。其中該第一主動樑界定該頂部之至少部 份外表面。 選擇性地，該運動部包含該致動器。 選擇性地，該第一主動樑界定該頂部之全部面積的至 少 3 0 % 。 選擇性地，該噴嘴開口被界定在該運動部內，使得該 噴嘴開口可相對於該底部運動。 選擇性地，該致動器可相對於該噴嘴開口運動。 選擇性地，扭曲樑元件界定該第一樑，該扭曲樑元件 具有複數的接觸樑構件。 選擇性地，該扭曲樑元件包含複數較長的樑構件和至 少一較短的樑構件，每一較長的樑構件沿著該第一樑的縱 軸線延伸，且被橫越該第一樑的橫軸線延伸之較短的樑構 件互連。 選擇性地，該複數樑其中之一包含多孔材料。 選擇性地，該多孔材料是具有介電常數2或更少之多 孔二氧化矽。 選擇性地，該熱彎曲致動器更包含介於該第一樑和該 第二樑之間的第三絕緣樑。 選擇性地，該第三絕緣樑包含多孔材料。 選擇性地，該第一樑熔合或接合至該第二樑。 選擇性地，該第二樑包含多孔材料。 選擇性地，至少部份的該第一樑和該第二樑相隔開。 -13- 200824914 (11) ^ 選擇性地，該第一樑包含的材料是選自包含氮化鈦、 . 氮化鈦鋁、和鋁合金的群組。 選擇性地，該第一樑包含鋁合金。 選擇性地，該鋁合金包含鋁和具有超過1 00 Gpa楊氏 模數的至少一種其他金屬。 選擇性地，該至少一種金屬是選自包含釩、錳、鉻、 鈷、和鎳的群組。 選擇性地，該合金包含鋁和釩。 選擇性地，該合金包含至少8 0%的鋁。 本發明的第六方面提供一種熱彎曲致動器，其具有複 數長形懸臂樑。該致動器包括：一第一主動樑，用以連接 至驅動電路，扭曲樑元件界定該第一樑，該扭曲樑元件具 有複數的接觸樑構件；和一第二被動樑，機械式地連動該 第一樑，使得當電流通過該第一樑時，該第一樑相對於該 第二樑膨脹，導致該致動器彎曲。其中該複數的接觸樑構 φ 件包含複數較長的樑構件和至少一較短的樑構件，該複數 較長的樑構件沿著該第一樑的縱軸線延伸，該較短的樑構 件橫越該第一樑的橫軸線延伸，且互連較長的樑構件。 選擇性地，藉由位在該致動器之一端的一對電性接點 ，該第一樑連接至該驅動電路。 選擇性地，該第一接點連接至該扭曲樑元件的第一端 ，且第二電性接點連接至該扭曲樑元件的第二端。 選擇性地，該複數樑其中之一包含多孔材料。 選擇性地，該多孔材料是具有介電常數2或更少之多 -14- 200824914 (12) 孔二氧化矽。 在另一方面提供一種熱彎曲致動器，其更 第一樑和該第二樑之間的第三絕緣樑。 選擇性地，該第三絕緣樑包含多孔材料。 選擇性地，該第一樑熔合或接合至該第二 選擇性地，該第二樑包含多孔材料。 選擇性地，至少部份的該第一樑和該第二 選擇性地，該第一樑包含的材料是選自包 氮化鈦鋁、和鋁合金的群組。 本發明在另一方面提供一種噴墨噴嘴組合 一噴嘴腔室，具有噴嘴開口和墨水入口；和一 器，具有複數懸臂樑，用以將墨水噴射經過該 該致動器包括：一第一主動樑，用以連接至驅 曲樑元件界定該第一樑，該扭曲樑元件包含複 構件；和一第二被動操，機械式地連動該第一 電流通過該第一樑時，該第一元件相對於該第 導致該致動器彎曲。其中該複數的接觸樑構件 長的樑構件和至少一較短的樑構件，該複數較 沿著該第一樑的縱軸線延伸，該較短的樑構件 樑的橫軸線延伸，且互連較長的樑構件。 選擇性地，該噴嘴腔室包括底部和具有運 ，藉此，該致動器的致動將該運動部朝該底部 選擇性地，該運動部包含致動器。 選擇性地，該第一主動樑界定該頂部之全 包含介於該 樑。 樑相隔開。 含氮化鈦、 體，包含： 熱彎曲致動 噴嘴開口。 動電路，扭 數的接觸樑 樑，使得當 二樑膨脹， 包含複數較 長的樑構件 橫越該第一 動部的頂部 運動。 部面積的至 -15- 200824914 (13) 少 3 0 % 〇 選擇性地，該第一主動樑界定該噴嘴腔室之至少部份 外表面。 選擇性地，該噴嘴開口被界定在該運動部內，使得該 噴嘴開口可相對於該底部運動。 選擇性地，該致動器可相對於該噴嘴開口運動。 在另一方面提供一種噴迫噴嘴組合體，其更包含位在 該致動器之一端的一對電性接點。該等電性接點提供該扭 曲樑元件和該驅動電路之間的電性連接。 選擇性地，第一電性接點連接至該扭曲樑元件的第一 端，且第二電性接點連接至該扭曲樑元件的第二端。 【實施方式】 微電機機械系統熱彎曲致動器（或熱彈性致動器）通常 包含呈一主動元件和一被動元件形式的一對元件，該被動 元件限制主動元件的線性膨脹。主動元件相對於被動元件 需要遭受較大的熱彈性膨脹，藉此提供彎曲運動。主動元 件和被動元件可熔合或黏合在一起以得最大的構造性整合 、或相分隔開以使被動元件熱損失最小化。 至此，我們已描述氮化鈦是作爲熱彎曲致動器中主動 熱彈性元件的合適選擇（candidate^例如見US 641 61 67)。 在例如申請人的美國第US 6428 1 3 3號專利中描述之其他 適合的材料有TiB2、MoSi2、TiAIN。 因爲其高熱膨脹和低密度，所以鋁是用做主動熱彈性 -16- 200824914 (14) ^ 元件的較佳選擇。但是鋁受到相對低的楊氏模數之苦，此 • 點減損鋁整體的熱彈性效率。因此，鋁先前不被認爲是用 做主動熱彈性元件的合適材料。 但是現在已發現鋁合金是用做熱彈性主動元件的優良 材料’因爲其結合局熱膨脹、低密度、和筒楊氏模數的有 利性質。 鋁通常和至少一種具有楊氏模數大於lOOGpa的金屬 形成合金。鋁通常和選自下列群組中的至少一種金屬形成 ^ 合金，該群組包含：釩、鍤、鉻、銘、鎳。令人驚課的是 已經發現，當鋁和該等金屬形成合金時，鋁的優良熱膨脹 性質並沒有減損。 合金選擇性地包含至少60% 、選擇性地至少70% 、選 擇性地至少80% 、或選擇性地至少90%的鋁（A1)。 圖1顯示呈懸臂樑20 1形成的雙壓電晶片熱彎曲致動器 200，該懸臂樑201固定至柱202。懸臂樑201包含結合 • (bond)至二氧化矽之上被動樑220的下主動樑210。致動器 200的熱彈性效率相較於包含有（1 )100% Α1、（Π)95% Al( 鋁）/5% V(釩）、（ΙΠ)9〇% A1/10% V。 藉由以短的電性脈衝刺激主動樑2 1 0並量測建立3m/s 峰値振盪速度所需的能量（以雷射千涉計決定）’而比較熱 彈性效率。其結果顯示於下表中： -17- 200824914 (15)200824914 (1). [Technical Field] The present invention relates to a thermal bending actuator which has been developed mainly for providing an improved ink jet nozzle which ejects ink by thermal bending actuation. [Prior Art] This application has previously inserted an excessive phenomenon of a micro-electromechanical mechanical (MEMS) nozzle using thermal bending. Thermal bending actuation generally refers to a bending motion relative to another material produced by thermal expansion of a material having electrical current. The resulting bending motion can be used to selectively eject ink from the nozzle opening by movement of the vanes or vanes. The vanes or vanes generate pressure waves within the nozzle chamber. Some representative types of thermally curved inkjet nozzles are exemplified in the patents or patent applications listed in the cross-referenced section above. I would like to refer to the contents of these cases for reference. The ink jet nozzle' described in U.S. Patent No. 6,410,167, the entire disclosure of which is incorporated herein by reference. The actuator is in the form of an active beam beneath a conductive material (e.g., titanium nitride) that is fused to a driven beam above a non-conductive material (e.g., cerium oxide). The actuator is coupled to the arm by receiving a slot in the wall of the nozzle chamber. When current passes through the lower active beam, the actuator bends upwardly, with the result that the blade moves toward the nozzle opening defined at the top of the nozzle chamber, thereby ejecting ink droplets. The advantage of this design is the simplicity of its construction, which has the disadvantage of working with two relatively viscous inks facing the interior side of the nozzle chamber. -4 - 200824914 (2) The inkjet nozzle described in the Applicant's US Pat. No. 6,260, 953, the disclosure of which is incorporated herein by reference. The actuator is in the form of a serpeiitiiie core encasing the conductive material with a polymeric material. When actuated, the actuator bends toward the bottom of the nozzle chamber, increasing the pressure within the chamber and forcing ink droplets out of the nozzle opening defined in the top of the chamber. The nozzle opening is defined in the non-moving portion of the top. The advantage of this design is that only one face on the top of the motion has to work against the relatively viscous ink on the inside of the nozzle chamber. The disadvantage of this design is the structure of the actuator that coats the serpentine conductive element with the polymer material. It is difficult to obtain in the micro motor mechanical method. The ink jet nozzle described in the applicant's U.S. Patent No. 6, 623,001 contains a nozzle chamber having a movable top having a nozzle opening defined therein. The movable top is connected by an arm to a thermal bending actuator located outside the nozzle chamber. The actuator takes the form of an upper active beam and a lower passive beam. By separating the active beam from the passive beam, the thermal bending efficiency is maximized because the φ passive beam cannot be used as a heat sink for the active beam. When current is passed through the upper active beam, the movable top having the nozzle opening defined therein is rotated toward the bottom plate of the nozzle chamber, thereby being ejected through the nozzle opening. Since the nozzle opening moves with the top, the direction in which the droplet moves can be controlled by appropriately modifying the shape of the nozzle edge. The advantage of this design is that only one face of the top of the motion must work against ink that is relatively viscous on the inside of the nozzle chamber. Another advantage is that heat loss can be minimized by separate active and passive beam members. A disadvantage of this design is that the spaced apart active and passive beam members lose structural rigidity. There is therefore a need to improve the design of thermally curved inkjet nozzles to achieve more efficient -5 - 200824914 (3) ^ rate droplet ejection and improved mechanical robustness. SUMMARY OF THE INVENTION A first aspect of the present invention provides an inkjet nozzle assembly comprising: a nozzle chamber including a bottom portion and a top portion, the top portion having a nozzle opening defined therein, the top portion having a movement movable toward the bottom portion And a thermal bending actuator having a plurality of cantilever beams for ejecting ink through the nozzle opening. The actuator includes: a first active beam for connecting to the driving fe road, and a 'table passive unit' mechanically interlocking the first probe so that when current passes through the first beam, the first A beam expands relative to the second beam, causing the actuator to bend. Wherein the moving part comprises the actuator. Optionally, the first active beam defines at least 30% of the total area of the top. Optionally, the first active beam defines at least a portion of the outer surface of the top portion. φ Optionally, the nozzle opening is defined within the moving portion such that the nozzle opening is movable relative to the base. Optionally, the actuator is moveable relative to the nozzle opening. Optionally, the twisted beam member defines the first beam, the twisted beam member having a plurality of contact beam members. Optionally, the plurality of contact beam members comprise a plurality of longer beam members and at least one shorter beam member extending along a longitudinal axis of the first beam, the shorter beam members Extending across the transverse axis of the first beam and interconnecting the longer beam members. -6 - 200824914 (4) Stomach Optionally, one of the plurality of beams comprises a porous material. Optionally, the porous material is a porous oxidized chop having a dielectric constant of 2 or less. Optionally, the thermal bending actuator further comprises a third insulating beam between the first beam and the second beam. Optionally, the third insulating beam comprises a porous material. Optionally, the first beam is fused or joined to the second beam. Optionally, the second beam comprises a porous material. Optionally, at least a portion of the first beam and the second beam are spaced apart. Optionally, the first beam comprises a material selected from the group consisting of titanium nitride, titanium aluminum nitride, and aluminum alloy. Optionally, the first beam comprises an aluminum alloy. Optionally, the aluminum alloy comprises aluminum and at least one other metal having a Young's modulus of more than 1 〇〇 Gpa. Optionally, the at least one metal is selected from the group consisting of vanadium, manganese, chromium, 0, and nickel. Optionally, the alloy comprises aluminum and vanadium. Optionally, the alloy comprises at least 80% aluminum. A second aspect of the invention provides a thermal bending actuator having a plurality of elements. The actuator includes: a first active component for connecting to the driving circuit; and a second passive component mechanically interlocking the first component such that when current passes through the first component, the first component is opposite The second element expands causing the actuator to bend. Wherein the first component comprises an aluminum alloy. 200824914 (5), optionally, the aluminum alloy comprises aluminum and at least one other metal having a Young's modulus of more than 1 〇〇 Gpa. Optionally, the at least one metal is selected from the group consisting of vanadium, manganese, chromium, cobalt, and nickel. Optionally, the alloy comprises aluminum and vanadium. Optionally, the alloy comprises at least 80% aluminum. Optionally, the first and second elements are cantilever beams. Optionally, the first beam is fused or joined to the second beam along its longitudinal axis. Optionally, at least a portion of the first beam and the second beam are spaced apart thereby insulating the first beam and a portion of the second beam. Optionally, one of the plurality of elements comprises a porous material. Optionally, the porous material has a dielectric constant of about 2 or less. Optionally, a third insulating beam is interposed between the first beam and the second beam. The third insulating beam comprises a porous material. Optionally, the second beam comprises a porous material. Another aspect of the present invention provides an inkjet nozzle assembly comprising: a nozzle chamber having a nozzle opening and an ink inlet; and a thermal bending actuator having a plurality of cantilever beams for ejecting ink through the nozzle opening . The actuator includes: a first active beam for connecting to the driving circuit; and a second passive beam mechanically interlocking the first beam such that when current passes through the first beam, the first beam is opposite The second beam expands, causing the actuation -8 - 200824914 (6) ' to bend. Wherein the first beam comprises an aluminum alloy. - Optionally, the nozzle chamber comprises a bottom and a top having a moving portion whereby actuation of the actuator moves the moving portion towards the bottom. Optionally, the moving portion includes an actuator. Optionally, the first active beam defines at least 30% of the total area of the top. Optionally, the first active beam defines at least a portion of an outer surface of the nozzle chamber. Optionally, the nozzle opening is defined within the moving portion such that the nozzle opening is movable relative to the base. A third aspect of the invention provides a thermal bending actuator having a plurality of elements. The actuator includes: a first active component for connecting to the driving circuit; and a second passive component mechanically interlocking the first component such that when current passes through the first component, the first component is opposite The second element expands causing the actuator to bend. Wherein one of the plurality of elements comprises a porous material. Optionally, the porous material has a dielectric constant of about 2 or less. Optionally, the porous material is porous ceria. Optionally, the first and second beams are cantilever beams. In another aspect, a thermal bending actuator is provided that further includes a third insulating beam between the first beam and the second beam. Optionally, the third insulating beam comprises a porous material. Optionally, the first beam is fused or joined along its longitudinal axis to the ninth - 200824914 (7) ^ two beam. _ Optionally, the second beam comprises a porous material. Optionally, the first component comprises a material selected from the group consisting of titanium nitride, titanium aluminum nitride, and aluminum alloy. Optionally, the first beam comprises an aluminum alloy. Optionally, the aluminum alloy comprises aluminum and at least one other metal having a Young's modulus in excess of 00 Gpa. Optionally, the at least one metal is selected from the group consisting of vanadium, manganese, chromium, cobalt, and nickel. Optionally, the alloy comprises aluminum and vanadium. Optionally, the alloy comprises at least 80% aluminum. Another aspect of the present invention provides an inkjet nozzle assembly comprising: a nozzle chamber having a nozzle opening and an ink inlet; and a thermal bending actuator having a plurality of cantilever beams for ejecting ink through the nozzle opening . The actuator includes: a first active beam for connecting to the drive circuit; and φ a second passive beam mechanically interlocking the first beam such that when current passes through the first beam, the first beam The actuator is bent relative to the expansion of the second beam. Wherein one of the plurality of beams comprises a porous material. Optionally, the nozzle chamber includes a bottom portion and a top portion having a moving portion whereby actuation of the actuator moves the moving portion toward the bottom portion. Optionally, the moving portion includes an actuator. Optionally, the first active beam defines at least 30% of the total area of the top. Optionally, the first active beam defines at least a portion of the nozzle chamber -10- 200824914 (8) * outer surface. Optionally, the nozzle opening is defined within the moving portion such that the nozzle opening is movable relative to the bottom portion. A fourth aspect of the invention provides an inkjet nozzle assembly 'comprising: a nozzle chamber including a bottom portion and a top portion, the top portion having a nozzle opening defined therein, the top portion having a moving portion movable toward the bottom portion; and a A thermal bending actuator having a plurality of cantilever beams for ejecting ink through the nozzle opening. The actuator includes: a first active beam for connecting to the driving circuit; and a second passive beam mechanically interlocking the first beam such that when current passes through the first beam, the first beam is opposite The second beam expands, causing the actuator to bend. Optionally, the first active beam defines at least 30% of the total area of the top. Optionally, the first active beam defines at least a portion of the outer surface of the top portion. φ Optionally, the nozzle opening is defined within the moving portion such that the nozzle opening is movable relative to the base. Optionally, the actuator is moveable relative to the nozzle opening. Optionally, the twisted beam member defines the first beam, the twisted beam member having a plurality of contact beam members. Optionally, the plurality of contact beam members comprise a plurality of longer beam members and at least one shorter beam member, the plurality of longer beam members extending along the longitudinal axis of the first beam 'the shorter beam members Extending across the transverse axis of the first machine and interconnecting the longer beam members. -11 - 200824914 (9) _ Optionally, one of the plurality of beams comprises a porous material. Optionally, the porous material is a porous cerium oxide having a dielectric constant of 2 or less. Optionally, the thermal bending actuator further comprises a third insulating beam between the first beam and the second beam. Optionally, the third insulating beam comprises a porous material. Optionally, the first beam is fused or joined to the second beam. Optionally, the second beam comprises a porous material. Optionally, at least a portion of the first beam and the second beam are spaced apart. Optionally, the first beam comprises a material selected from the group consisting of titanium nitride, titanium aluminum nitride, and aluminum alloy. Optionally, the first beam comprises an aluminum alloy. Optionally, the aluminum alloy comprises aluminum and at least one other metal having a Young's modulus of more than 100 Gpa. Optionally, the at least one metal is selected from the group consisting of vanadium, manganese, chromium, φ cobalt, and nickel. Optionally, the alloy comprises aluminum and vanadium. Optionally, the alloy comprises at least 80% aluminum. A fifth aspect of the invention provides an inkjet nozzle assembly comprising: a nozzle chamber including a bottom portion and a top portion, the top portion having a nozzle opening defined therein, the top portion having a moving portion movable toward the bottom portion; and a A thermal bending actuator having a plurality of cantilever beams for ejecting ink through the nozzle opening. The actuator includes: a first active beam for connecting to the driving circuit; and a second passive beam mechanically interlocking the first beam such that when -12-200824914 (10) current flows through the first beam The first beam expands relative to the second beam, causing the actuator to bend. Wherein the first active beam defines at least a portion of the outer surface of the top portion. Optionally, the moving portion comprises the actuator. Optionally, the first active beam defines at least 30% of the total area of the top. Optionally, the nozzle opening is defined within the moving portion such that the nozzle opening is movable relative to the base. Optionally, the actuator is moveable relative to the nozzle opening. Optionally, the twisted beam member defines the first beam, the twisted beam member having a plurality of contact beam members. Optionally, the twisted beam element comprises a plurality of longer beam members and at least one shorter beam member, each longer beam member extending along a longitudinal axis of the first beam and being traversed by the first beam The shorter beam members of the transverse axis are interconnected. Optionally, one of the plurality of beams comprises a porous material. Alternatively, the porous material is a porous cerium oxide having a dielectric constant of 2 or less. Optionally, the thermal bending actuator further comprises a third insulating beam between the first beam and the second beam. Optionally, the third insulating beam comprises a porous material. Optionally, the first beam is fused or joined to the second beam. Optionally, the second beam comprises a porous material. Optionally, at least a portion of the first beam and the second beam are spaced apart. -13- 200824914 (11) ^ Optionally, the first beam comprises a material selected from the group consisting of titanium nitride, titanium aluminum nitride, and aluminum alloy. Optionally, the first beam comprises an aluminum alloy. Optionally, the aluminum alloy comprises aluminum and at least one other metal having a Young's modulus of more than 100 Gpa. Optionally, the at least one metal is selected from the group consisting of vanadium, manganese, chromium, cobalt, and nickel. Optionally, the alloy comprises aluminum and vanadium. Optionally, the alloy comprises at least 80% aluminum. A sixth aspect of the invention provides a thermal bending actuator having a plurality of elongated cantilever beams. The actuator includes a first active beam for connecting to a drive circuit, a twisted beam member defining the first beam, the twisted beam member having a plurality of contact beam members, and a second passive beam mechanically coupled The first beam is such that when current passes through the first beam, the first beam expands relative to the second beam, causing the actuator to bend. Wherein the plurality of contact beam members comprise a plurality of longer beam members and at least one shorter beam member extending along a longitudinal axis of the first beam, the shorter beam members being transverse The transverse axis of the first beam extends and interconnects the longer beam members. Optionally, the first beam is coupled to the drive circuit by a pair of electrical contacts located at one end of the actuator. Optionally, the first contact is coupled to the first end of the twisted beam member and the second electrical contact is coupled to the second end of the twisted beam member. Optionally, one of the plurality of beams comprises a porous material. Optionally, the porous material has a dielectric constant of 2 or less -14-200824914 (12) pore cerium oxide. In another aspect, a thermal bending actuator is provided that further includes a third insulating beam between the first beam and the second beam. Optionally, the third insulating beam comprises a porous material. Optionally, the first beam is fused or joined to the second selectively, the second beam comprising a porous material. Optionally, at least a portion of the first beam and the second selectively, the first beam comprises a material selected from the group consisting of titanium aluminum nitride, and aluminum alloy. In another aspect, the present invention provides an ink jet nozzle assembly having a nozzle chamber having a nozzle opening and an ink inlet; and a device having a plurality of cantilever beams for ejecting ink through the actuator including: a first active a beam for connecting to the flexure beam member defining the first beam, the twisted beam member including a composite member; and a second passive operation for mechanically interlocking the first current through the first beam, the first member The actuator is bent relative to the first. Where the plurality of contact beam members are long beam members and at least one shorter beam member, the plurality is extending along a longitudinal axis of the first beam, the shorter beam member beams extending transversely and interconnecting Long beam members. Optionally, the nozzle chamber includes a bottom portion and is actuated whereby actuation of the actuator selectively moves the moving portion toward the bottom portion, the moving portion containing an actuator. Optionally, the first active beam defines the entirety of the top portion being included in the beam. The beams are separated. Containing titanium nitride, body, including: Thermal bending actuated nozzle opening. The moving circuit, the twisted contact beam, causes the two beams to expand, including a plurality of longer beam members traversing the top of the first moving portion. The area of the area is -15-200824914 (13) less than 30% 〇 Optionally, the first active beam defines at least a portion of the outer surface of the nozzle chamber. Optionally, the nozzle opening is defined within the moving portion such that the nozzle opening is movable relative to the base. Optionally, the actuator is moveable relative to the nozzle opening. In another aspect, an injection nozzle assembly is provided that further includes a pair of electrical contacts located at one end of the actuator. The electrical contacts provide an electrical connection between the torsion beam member and the drive circuit. Optionally, a first electrical contact is coupled to the first end of the twisted beam member and a second electrical contact is coupled to the second end of the twisted beam member. [Embodiment] A micro-mechanical mechanical system thermal bending actuator (or thermoelastic actuator) typically includes a pair of elements in the form of an active element and a passive element that limits the linear expansion of the active element. The active element is subject to greater thermoelastic expansion relative to the passive element, thereby providing a bending motion. The active and passive components can be fused or bonded together for maximum structural integration or phase separation to minimize heat loss from the passive components. So far, we have described titanium nitride as a suitable choice for active thermoelastic elements in thermal bending actuators (candidate^ see, for example, US 641 61 67). Other suitable materials such as those described in U.S. Patent No. 6,428,133, the entire disclosure of which is incorporated herein by reference. Because of its high thermal expansion and low density, aluminum is the preferred choice for active thermoelastic -16-200824914 (14)^ components. However, aluminum suffers from a relatively low Young's modulus, which detracts from the overall thermoelastic efficiency of aluminum. Therefore, aluminum was not previously considered to be a suitable material for use as an active thermoelastic component. However, aluminum alloys have now been found to be excellent materials for use as thermoelastic active elements because of their combined properties of thermal expansion, low density, and tube Young's modulus. Aluminum is usually alloyed with at least one metal having a Young's modulus greater than 100 GPa. The aluminum is usually formed into an alloy with at least one metal selected from the group consisting of vanadium, niobium, chromium, indium, and nickel. It is surprising that it has been found that when aluminum and these metals form alloys, the excellent thermal expansion properties of aluminum are not impaired. The alloy optionally comprises at least 60%, optionally at least 70%, optionally at least 80%, or alternatively at least 90% aluminum (A1). 1 shows a bimorph thermal bending actuator 200 formed in a cantilever beam 201 that is secured to a post 202. The cantilever beam 201 includes a lower active beam 210 bonded to the passive beam 220 above the ceria. The thermoelastic efficiency of the actuator 200 is compared to that of (1) 100% Α1, (Π) 95% Al (aluminum) / 5% V (vanadium), (ΙΠ) 9〇% A1/10% V. The thermoelastic efficiency is compared by stimulating the active beam 2 1 0 with a short electrical pulse and measuring the energy required to establish a 3 m/s peak-to-peak oscillation speed (determined by laser measurements). The results are shown in the table below: -17- 200824914 (15)
主動探材料 達到峰値振盪速度所需的能量 100% A1 466 nJ 95% Al/5% V 224 nJ 90% Al/10% V 219 nJ 因此，95% Al/5% V的合金比供比較的100% A1裝置 _ 需要的能量少了 2.08倍。再者，90% A1/10% V的合金比供 比較的100% A1裝置需要的能量少了 2.12倍。因此結論是 :在微電機機械應用的範圍（包括用於噴墨噴嘴的熱彎曲 致動器）中，鋁合金是用做主動熱彈性元件的優良選擇。 包含有熱彎曲致動器的噴墨噴嘴 下文將描述典型的噴墨噴嘴，其可合倂熱彎曲致動器 ，該致動器具有包含鋁合金的主動元件。 包含有熔合熱彎曲致動器的噴嘴組合體 參考圖2(A)和3，其顯示第一實施例之噴嘴組合體100 的示意例示。如同US6416 1 67所描述者，噴嘴組合體100 是以微電機機械系統的方法形成在矽基板3的鈍化層2。噴 嘴組合體100包含噴嘴腔室1，噴嘴腔室1具有頂部4和側壁 5。墨水6藉由墨水入孔槽道7充滿噴嘴腔室1，墨水入孔槽 道7蝕刻穿過基板3。噴嘴腔室1更包括噴嘴開口 8，以噴射 來自噴嘴腔室的墨水。如圖2(A)所示，墨水彎月面20被約 -18- 200824914 (16) - 束在噴嘴開口 8的整個邊緣（i:im)21。 . 噴嘴組合體100更包含位在噴嘴腔室1內側的葉片9， 該葉片9經由壁11而互連至位在噴嘴腔室外部的致動器10 。如圖2較清楚地顯示者，臂延伸經過噴嘴腔室1內的槽12 。槽1 2內之墨水的表面張力足以提供對容置在噴嘴腔室j 內之墨水的流體性密封。 致動器10包含複數狹長的致動器單元13，該等致動器 單元1 3在橫方向上相隔開。每一致動器單元在臂丨丨和安裝 在鈍化層2上的固定柱14之間延伸。因次，柱14提供了致 動器10之彎曲運動的樞軸。 每一致動器單元13包含第一主動樑15、和熔合至主動 樑之上表面的第二被動樑1 6。主動樑1 5具傳導性，且連接 至基板3之CMOS層內的驅動電路。被動樑16通常爲非傳 導性。 現在參考圖2(B)，當電流流經主動樑15時，主動樑被 φ 加熱且遭受相對於被動樑16的熱膨脹。此造成致動器10向 上彎曲運動，該運動放大成葉片9的旋轉運動。 此結果的葉片運動使得墨水彎月面20周圍的壓力普遍 增力卩，如圖2(B)所示，墨水彎月面20快速地膨脹擴張。然 後，致動器停止致動，此使得葉片9回到其靜止位置（圖 2(C)) 〇 在此脈衝循環期間，墨水液滴1 7從噴嘴開口 8射出’ 且墨水6同時經由墨水入孔7回流進入噴嘴腔室1。如圖 2(C)所示，噴嘴邊緣21外側之墨水的向前動量和對應的回 -19- 200824914 (17) ^ 流，導致液滴1 7普遍頸縮和分離，該液滴繼續向列印介質 . 。崩潰的彎月面20使墨水6經由墨水入口 7被吸入噴嘴腔室 1。噴嘴腔室1被再塡充，以再度到達圖2(A)的位置，且噴 嘴組合體1〇〇準備射出另一墨水液滴。 參考圖3，可看到致動器單元1 3相對於其橫向軸線呈 推拔，其具有連接至柱1 4的較窄末端、和連接至臂1 1的的 較寬末端。此推拔確保最大的阻抗式加熱發生在柱14附近 ，藉此使熱彈性彎曲運動最大化。被動樑1 6通常包含二氧 ® 化矽或以化學氣相沉積法（CVD)沉積的四乙基正矽酸塩 (TEOS) 〇如圖2_4所示，臂1 1是由相同的材料製成。 在本發明中，主動樑1 5包含鋁合金，較佳是上述的 鋁-釩合金。 包含有相隔離之熱彎曲致動器的噴嘴組合體 現在參考圖5-8，其顯示第二實施例之噴嘴總成300。 φ 參考附圖的圖5-7，噴嘴組合體300(以微電機機械的技術） 建構在基板301上。該基板301界定墨水供給孔3 02經過六 角形入口 3 03 (其可爲任何適當的結構）連通於腔室304。腔 室由底部3 05、頂部3 06、和以可伸縮的方式重疊之周圍側 壁3 07、3 08所界定。設計側壁3 07(從頂部3 06向下延伸 (depending))的尺寸，使其能側壁3 08(從底部3 05向上延伸 )內上下運動。 噴射噴嘴是由位在頂部306內的邊緣3 09所形成，以界 定供從噴嘴腔室噴射墨水的開口，如下文將描述者。 -20- 200824914 (18) ‘ 頂部3 06和向下延伸的側壁307由彎曲致動器310所支 秦 撐’該彎曲致動器310通常由焦耳（Joule)加熱懸臂所形成 的層而製成’該焦耳加熱懸臂被未加熱懸臂所限制。所以 加熱焦耳加熱懸臂會在焦耳加熱懸臂和未加熱懸臂之間產 生差異的膨脹，此使得彎曲致動器310彎曲。 彎曲致動器的近端311固定至基板301，且被錨構件 312防止向後運動，此將於下文描述。遠端313被固定至和 支撐噴墨噴嘴的頂部3 06和側壁3 07。 在使用中，墨水以任何合適的方式經過通道302和開 口 3 3被供給進入噴嘴腔室，但是通常像先前參考共同申請 的專利申請案所描述者。當希望從噴嘴腔室噴射墨水液滴 時，電流供給至彎曲致動器3 1 0，使得致動器彎曲至圖6所 示的位置，且將頂部306朝底部305向下運動。此相對運動 減少噴嘴腔室的熔積，使得墨水經過噴嘴邊緣3 09向上突 出呈（圖6)在314處所示者，其藉由墨水中的表面張力形成 ^ 液滴。 當電流撤離彎曲致動器310時，致動器回復至如圖7所 示之直的結構，將噴嘴腔室的頂部306向上運動至原始位 置。部份形成墨水液滴的動量使得液滴繼續向上運動，而 形成如圖7所示的墨水液滴，其投射至相鄰的紙表面或其 他待列印的物品上。 在本發明的一種形式中，相較於噴嘴腔室的橫剖面， 底部3 05中的開口 3 03相對地大。當頂部3 06向下運動時， 藉由孔3 0 2之側壁內、和從墨水儲存器（未不）連通至開口 -21 · 200824914 (19) ^ 302之供給管內的黏性拉力，使得墨水液滴經過噴嘴邊緣 - 3 0 9噴射。 爲了在致動期間（亦即在彎曲致動器310彎曲的期間） 防止墨水從噴嘴腔室洩漏，流體性密封形成在側壁3 07和 308之間，如同現在要參考圖7、8近一步描述者。 在頂部306和底板305相對運動期間，藉由以表面張力 確保墨水被保持在墨水腔室內的幾何構造，墨水被保持在 噴嘴腔室中。爲了此目的，在向下延伸的側壁3 07和像邵 延伸的側壁308之相互面對的表面316之，設有非常小的間 隙。如圖8中可清楚看見者，藉由兩側壁的接近，墨水（顯 示如黑色陰影區）被限制在向下延伸側壁3 07和向上延伸側 壁之向內表面3 1 6之間的小孔內；該兩側壁的接近，藉由 表面張力確保整個自由開口 3 1 7的墨水「自我密封」。 爲了防止可能破壞表面張力之雜質或其他因素使墨水 脫離表面張力的限制，以面向上槽道的方式設置向上延伸 φ 的側壁3 08，該槽道不僅具有內表面3 1 6而且具有相間隔之 平行外表面3 1 8，並在兩表面間形成U形槽道3 1 9。脫離 表面3 07和3 1 6之間表面張力的的墨水液滴，溢流進入U 形槽道。溢流的墨水被保持在槽道，而非「擴展（wicking) 」至噴嘴底層的整個表面。以此方式，形成雙壁流體密封 ，且其能有效率地將墨水保持在運動的噴嘴機構內。 參考圖8，可看到致動器310包含配置在上方且和第二 被動樑3 60相間隔的第一主動樑3 58。藉由將二樑相隔開， 可使從主動樑3 5 8至被動樑360熱傳輸最小化。因此，此分 -22- 200824914 (20) 隔的配置具有將熱彈性效率最大化的優點。在本發明中， 主動樑2 58可包含鋁合金，如上所述，例如鋁釩合金。 界定運動噴嘴頂部的熱彎曲致動器 圖5-8所例示的實施例顯示噴嘴組合體3 00，其包含具 有頂部3 06的噴嘴腔室304，該頂部3 06相對腔室的底部305 運動。藉由設在噴嘴腔室305外部的雙層熱彎曲致動器310 ，可動的頂部306被致動以朝底部3 05運動。 因爲只有運動構造的一個面必須抵抗黏性墨水而工作 ，所以運動頂部降低液滴噴射能量。但是需要增加液滴噴 射之動力的量。藉由增加動力的量，可使用較短的脈衝寬 度以提供相同量的能量。藉由較短的脈衝寬度，可獲得改 善的液滴噴射特徵。 增加致動器動力的一種手段是增加致動器的尺寸。但 是在圖5-8所示的噴嘴設計中，增加致動器尺寸顯然會不 利地影響噴嘴的空間，此爲製造高解析度頁寬列印頭時所 不樂見的。 圖9-1 2所示的噴嘴組合體400，提供此問題的解決之 道。噴嘴組合體400包含噴嘴腔室401，其形成在矽基板 403的鈍態金氧互補半導體（CMOS)層402上。噴嘴腔室是 由頂部404和從頂部延伸至鈍態金氧互補半導體層402的側 壁405所界定。藉由和墨水供給槽道407呈流體連通的墨水 入口 406，墨水被供給至噴嘴腔室401。該墨水供給槽道 407從矽基板的背側接收墨水。藉由界定在頂部4〇4中的噴 -23- 200824914 (21) - 嘴開口 408，墨水被從噴嘴腔室噴射。噴嘴開口 408相對於 , 墨水入口 406偏置。 如圖10更清楚地顯示，頂部404具有運動部409，其界 定頂部之全部區域的實質部份。運動部409通常界定頂部 404之全部區域的至少20% 、至少30% 、至少40% 、或至 少5 0% 。在圖9-1 2所示的實施例中，噴嘴開口 408和噴嘴 邊緣41 5被界定在運動部409中，使得噴嘴開口 40 8和噴嘴 邊緣415隨著運動部409運動。 ® 噴嘴組合體400的特徵在於運動部被熱彎曲致動器4 1 0 所界定，該熱彎曲致動器具有平坦的上主動樑4 1 1和平坦 的下被動樑412。因此，致動器410通常界定頂部404之全 部區域的至少20°/。、至少30% 、至少4〇% 、或至少50% 。 對應地，上主動樑411通常界定頂部404之全部區域的至少 2 0 % 、至少3 0 % 、至少4 0 % 、或至少5 0 % 。 如圖9和1 0所示，至少部份的上主動樑4 1 1和下被動樑 0 412相隔開，以使該二樑的熱絕緣最大化。更明確地說’ 鈦層被用做上主動層411(包含有氮化鈦）和下被動層412( 包含有二氧化矽）之間的橋階層413。藉由使從主動層411 至被動層41 2的熱傳輸最小化，此間隙41 4改善致動器410 的整體效率。 但是，當然可瞭解在另一實施例中，主動樑411可直 接熔合或結合至被動樑4 1 2，以改善構造剛性。此設計修 飾仍在熟悉該項技藝者的範圍內，且包含在本發明範圍內 -24- 200824914 (22) ‘ 藉由鈦橋階層，主動樑4 1 1連接至一對接點4 1 6 (正極 ^ 和接地）°接點和金氧互補半導體層內的驅動電路相連接 〇 當要求從噴嘴腔室401噴射墨水液滴時，電流流經二 接點4 16之間得主動樑411。主動樑411被電流快速地加熱 ’且相對於被動樑412膨脹，藉此使得致動器41 0(其界定 頂部404的運動部409)朝基板403向下彎曲。致動器401的 ^ 此運動’藉由快速增加噴嘴腔室40 1內側的壓力，而使墨 水從噴嘴開口 408噴射。當電流停止流動時，頂部404的運 動部409被允許返回到其靜止位置，此會從入口 406將墨水 吸入噴嘴腔室401，以準備下一次噴射。 因此，液滴噴射的原理類似上述關於噴嘴組合體3 00 的描述。但是由於界定頂部404之運動部409的熱彎曲致動 器410，所以有更大量的動力可供液滴噴射，因爲相較於 噴嘴組合體400的整體尺寸，主動樑411具有大的區域。 φ 參考圖12，可瞭解噴嘴組合體40(和此處所描述之全 部其他噴嘴組合體）可被複製成陣列的噴嘴組合體，以界 定列印頭或整合有電路的列印頭。整合有電路的列印頭包 含矽基板、形成在基板上的陣列噴嘴組合體（通常成列地 配置）、供噴嘴組合體用的驅動電路。複數整合有電路的 列印頭可鄰接或連接，以形成頁寬噴墨列印頭，如同例如 申請人較早的美國第1 0/85 449 1號（2 004/05/27申請）和第 1 0/014732號（2004/1 2/20申請）申請案所述者。茲將該等申 請案的內容倂入參考。 -25- 200824914 (23) 一 圖13至15所示的噴嘴組合體500類似噴嘴組合體400。 - 具有上主動樑5 1 1和下被動樑5 1 2的熱彎曲致動器5 i 0，界 定噴嘴腔室501之頂部504的運動部。因此，就增加動力而 言，噴嘴組合體500獲得和噴嘴組合體400相同的優點。 但是，對照噴嘴組合體400，噴嘴開口 5 08和邊緣515 並不是被頂部504的運動部所界定，而是被頂部504的固定 部所界定，使得在噴射液滴的期間，致動器5 1 0獨立於噴 嘴開口和邊緣而運動。此結構的優點在於其提供更容易控 制液滴飛行方向。 當然可瞭解鋁合金（由於其改善熱彎曲效率的固有優 點）可用做上述關於圖9 -1 5所示實施力所述之熱彎曲致動 器410和5 10二者任一的主動樑。 可將噴嘴組合體400和5 00建構成以類似申請人較早的 美國第606167號和第6788809號專利案噴墨噴嘴製造方法 的方式，使用合適的微電機機械技術。茲將該等專利案的 φ 內容倂入做參考。 在彎曲方向具最佳勁度的主動樑 現在參考圖11-15，可看到致動器410和510的上主動 樑4 1 1、5 1 1都包含扭曲的樑元件，其具有彎曲（在樑4丨〗的 情況）或蛇形（在樑5 1 1的情況）其中任一的結構。扭曲的樑 元件是長形的，且具有適於抵抗加熱之相對小的橫剖面面 積。此外，扭曲的結構使得樑元件的各末端，能連接至位 在致動器之一端的各接點，簡化噴嘴組合體的整體設計和 -26- 200824914 (24) 結構。 明確地參考圖14和15，長形樑元件520具有界定致動 器5 10之長形主動懸臂樑511的蛇形結構。蛇形樑52〇具有 平坦的扭曲路徑，其將第一電性接點5 1 6和第二電性接點 5 1 6連接。該等電性接點（正極和接地）位在致動器5 1 〇的一 端，且提供金氧互補半導體層5 02中驅動電路和主動樑511 之間的電性連接。 蛇形樑元件520是由標準的微影術蝕刻技述所製成， 且由複數接觸的構件所界定。一般而言，樑構件可被定義 做樑材料的固體部份，其沿著例如縱向或橫向大致線性地 延伸。樑元件520的樑構件包含較長的樑構件521和較短的 樑構件522。較長的樑構件521沿著長形懸臂樑51 1的縱向 軸線延伸，較短的樑構件522橫越長形懸臂樑51 1的橫向軸 線延伸。此蛇形樑元件520結構之優點是其提供懸臂樑511 在彎曲方向的最大勁度。在彎曲方向的勁度是有利的，因 爲其有利致動器5 1 0在每一致動之後彎曲回到其靜止位置 〇 應瞭解圖11所示供噴嘴組合體400用之彎曲主動樑結 構，獲得和上述關於噴嘴組合體500之結構相同或類似的 優點。在圖11中，縱向延伸之較長的樑構件顯示如421 ’ 而橫向延伸之互連較短的樑構件顯示如4 2 2。 使用多孔材料以改善熱效率 在上述全部的實施例中’和本申請人描述之其他貫施 27- 200824914 (25) 一 利的熱彎曲致動器，主動樑結合（bond)至被動樑以得構造 - 堅固性（見圖1和2 )，或者主動樑和被動樑相間隔以得最大 熱效率（見圖8)。各樑之間的空氣間隙所提供的熱效率當 然是所希望的。但是此熱效率的改善經常是以構造堅固性 和熱彎曲致動器之挫曲傾向爲代價。 美國第6 1 63 066號專利案描述多孔二氧化矽絕緣體， 其具有約2.0或以下的介電常數，茲將該專利案倂入做參 考。 β 該材料是藉由沉積碳化矽或將碳組件氧化而形成多孔 二氧化矽。藉由增加碳對矽的比値，可增加產生之多孔二 氧化矽的多孔性。已知多孔二氧化矽可用做積體電路中的 鈍化層，以降低寄生（parasitic)阻抗。 但是本案申請人已發現此類型的多材料，可用於改善 熱彎曲致動器的效率。多孔材料可用做主動樑和被動樑之 間的絕緣層、或用做被動樑本身。 φ 圖16顯示熱彎曲致動器600，其包含上主動樑601、下 被動樑602、和介於上主動樑與下被動樑之間的絕緣層6〇3 。絕緣樑包含多孔二氧化矽，而主動樑601和被動樑6〇2可 包含任何適合的材料，例如分別爲氮化鈦和二氧化矽。 絕緣層603的多孔性提供主動樑601和被動樑6〇2之間 優良的熱絕緣。絕緣層6 〇 3也提供具有構造堅固性的致動 器650。因此，致動器6〇〇結合上述圖1、2、8相關描述之 兩類型熱彎曲致動器的優點。 在另一實施例中，且如圖〗7所示，多孔材料可單純形 -28 - 200824914 (26) 成雙層熱彎曲致動器的被動層。因此，熱彎曲致動器650 包含上主動樑651(其包括氮化鈦）、和下被動樑652(其包 括多孔二氧化矽）。 當然可瞭解，圖16、17所示類型的熱彎曲致動器可倂 入任何合適的噴墨噴嘴或其他微電機機械系統裝置中。熱 效率和構造剛性的改善，使得此等致動器在任何微電機機 械系統應用中具吸引力，該應用要求機械性的致動器或換 能器。 圖16、17所示類型的熱彎曲致動器特別適合用在上述 的噴墨噴嘴組合體400、5 00中。熟悉該項技藝人士可瞭解 熱彎曲致動器410、510的適當修飾，可實現上述熱效率和 構造剛性的改善。 應瞭解上述熱彎曲致動器600、650中的主動樑構件61 、65 1，可包含此處所述的鋁合金，以進一步改善熱彎曲 效率。 . 當然可瞭解本發明只以例子的方式描述’且在本發明 的範圍內可做細節的修飾，該範圍被所附的請求項定義。 【圖式簡單說明】 圖1是雙層熱彎曲致動器的示意側視圖，其包含由鋁 釩合金所形成的主動樑； 圖2(A)-(C)是噴墨噴嘴組合體的示意側剖視圖，其包 含熔合的熱彎曲致動器在各階段的操作； 29- 200824914 (27) 圖3是圖2(A)所示噴嘴組合體的透視圖； 圖4是整合有電路之部份列印頭的的透視圖，其包含 如圖2(A)和圖3所示的陣列的噴嘴組合體； 圖5是噴墨噴嘴組合體之切除透視圖，其包含分隔開 的熱彎曲致動器和運動頂部構造； 圖6是圖5所示噴墨噴嘴組合體在致動結構時之切除透 視圖； 圖7是圖5所示噴墨噴嘴組合體在剛致動完畢時之切除 透視圖； 圖8是圖6所示噴墨噴嘴組合體之側剖視圖； 圖9是噴墨噴嘴組合體之側剖視圖，其包含頂部，該 頂部具有由熱彎曲致動器所界定之運動部； 圖10是圖9所示噴嘴組合體之切除透視圖； 圖1 1是圖10所示噴嘴組合體之透視圖； 圖1 2是圖1 0所示陣列噴嘴組合體之切除透視圖； 圖1 3是另一實施例之噴墨噴嘴組合體之側剖視圖，其 包含頂部，該頂部具有由熱彎曲致動器所界定之運動部； 圖1 4是圖1 3所示噴嘴組合體之切除透視圖； 圖15是圖13所示噴嘴組合體之透視圖； 圖1 6是三層熱彎曲致動器的示意側視圖，其包含由多 孔材料所形成的絕緣樑，該絕緣樑被夾在中間；和 圖17是三層熱彎曲致動器的示意側視圖，其包含由多 孔材料所形成的被動樑。 -30- 200824914 (28) ^ 【主要元件符號說明】 . 1 :(噴嘴）腔室 2 :鈍化層 3 :(矽）基板 4 :頂部 5 :側壁 6 :墨水 7 :(墨水入口）槽道 8 :(噴嘴）開口 9 :葉片 1 〇 :致動器 1 1 :臂 12 :槽 1 3 :致動器單元 1 4 :固定柱 0 15 :(第一）主動樑 16 :(第二）被動樑 17 :(墨水）液滴 20 :(墨水）彎月面 21 :邊緣 100 :噴嘴組合體 200 :(熱彎曲）致動器 201 :懸臂樑 202 ：柱 200824914 (29) 2 10 ： 220: 3 00 ： 3 01 ： 3 02 ： 3 03 ： 3 04 ： 3 05 ：The energy required for the active probe material to reach the peak-to-peak oscillation speed is 100% A1 466 nJ 95% Al/5% V 224 nJ 90% Al/10% V 219 nJ Therefore, the alloy of 95% Al/5% V is compared 100% A1 device _ requires 2.08 times less energy. Furthermore, the 90% A1/10% V alloy requires 2.12 times less energy than the comparable 100% A1 unit. The conclusion is therefore that aluminum alloys are an excellent choice for use as active thermoelastic components in the range of microelectromechanical applications, including thermal bending actuators for inkjet nozzles. Inkjet Nozzle Comprising a Thermal Bending Actuator A typical inkjet nozzle will be described hereinafter which can be combined with a thermal bending actuator having an active element comprising an aluminum alloy. Nozzle assembly incorporating a fused thermal bending actuator Referring to Figures 2(A) and 3, there is shown a schematic illustration of the nozzle assembly 100 of the first embodiment. As described in US Pat. No. 6,416,67, the nozzle assembly 100 is formed in the passivation layer 2 of the ruthenium substrate 3 in a micromechanical mechanical system. The nozzle assembly 100 includes a nozzle chamber 1 having a top portion 4 and side walls 5. The ink 6 fills the nozzle chamber 1 by the ink inlet channel 7, and the ink inlet channel 7 is etched through the substrate 3. The nozzle chamber 1 further includes a nozzle opening 8 to eject ink from the nozzle chamber. As shown in Fig. 2(A), the ink meniscus 20 is bundled around the entire edge (i:im) 21 of the nozzle opening 8 by about -18-200824914 (16). The nozzle assembly 100 further includes a vane 9 positioned inside the nozzle chamber 1 which is interconnected via a wall 11 to an actuator 10 located outside the nozzle chamber. As shown more clearly in Figure 2, the arms extend through slots 12 in the nozzle chamber 1. The surface tension of the ink within the slot 12 is sufficient to provide a fluid tight seal to the ink contained within the nozzle chamber j. The actuator 10 includes a plurality of elongated actuator units 13 that are spaced apart in the lateral direction. Each actuator unit extends between the arm shank and a mounting post 14 mounted on the passivation layer 2. In turn, the post 14 provides a pivot for the bending motion of the actuator 10. Each actuator unit 13 includes a first active beam 15 and a second passive beam 16 fused to the upper surface of the active beam. The active beam 15 is conductive and is connected to a drive circuit within the CMOS layer of the substrate 3. Passive beam 16 is typically non-conductive. Referring now to FIG. 2(B), when current flows through the active beam 15, the active beam is heated by φ and subjected to thermal expansion relative to the passive beam 16. This causes the actuator 10 to bend upwardly, which is amplified into the rotational motion of the blade 9. The resulting blade motion causes the pressure around the ink meniscus 20 to generally increase, as shown in Fig. 2(B), the ink meniscus 20 rapidly expands and expands. Then, the actuator stops actuating, which causes the blade 9 to return to its rest position (Fig. 2(C)). During this pulse cycle, the ink droplets 17 are ejected from the nozzle opening 8 and the ink 6 is simultaneously introduced through the ink. The orifice 7 is recirculated into the nozzle chamber 1. As shown in Fig. 2(C), the forward momentum of the ink outside the nozzle edge 21 and the corresponding back -19-200824914 (17) ^ flow, resulting in the general necking and separation of the droplets 17. The droplet continues to the nematic Printing media. The collapsed meniscus 20 causes the ink 6 to be drawn into the nozzle chamber 1 via the ink inlet 7. The nozzle chamber 1 is refilled to reach the position of Fig. 2(A) again, and the nozzle assembly 1 is ready to eject another ink droplet. Referring to Figure 3, it can be seen that the actuator unit 13 is pushed out relative to its transverse axis with a narrower end connected to the post 14 and a wider end connected to the arm 11. This push-out ensures that the maximum resistive heating occurs near the column 14, thereby maximizing the thermoelastic bending motion. The passive beam 16 typically contains dioxin® or cerium tetraethyl orthosilicate (TEOS) deposited by chemical vapor deposition (CVD). As shown in Figure 2_4, the arms 11 are made of the same material. . In the present invention, the active beam 15 comprises an aluminum alloy, preferably the above-described aluminum-vanadium alloy. Nozzle Assembly Comprising a Isolated Thermal Bending Actuator Referring now to Figures 5-8, a nozzle assembly 300 of the second embodiment is shown. φ Referring to Figures 5-7 of the drawings, a nozzle assembly 300 (in the art of a micro-electromechanical machine) is constructed on a substrate 301. The substrate 301 defines an ink supply aperture 312 that communicates with the chamber 304 via a hexagonal inlet 303 (which may be of any suitable configuration). The chamber is defined by a bottom 3 05, a top 306, and surrounding side walls 3 07, 308 that overlap in a telescopic manner. The dimensions of the side wall 3 07 (downward from the top 3 06) are designed such that it can move up and down within the side wall 3 08 (extending upward from the bottom 3 05). The spray nozzle is formed by an edge 309 located in the top portion 306 to define an opening for ejecting ink from the nozzle chamber, as will be described below. -20- 200824914 (18) 'The top 3 06 and the downwardly extending side wall 307 are supported by a bending actuator 310. The bending actuator 310 is typically made of a layer formed by a Joule heating cantilever. 'The Joule heating cantilever is limited by the unheated cantilever. Therefore, heating the Joule heating cantilever produces a differential expansion between the Joule heating cantilever and the unheated cantilever, which causes the bending actuator 310 to bend. The proximal end 311 of the bending actuator is fixed to the base plate 301 and is prevented from moving backward by the anchor member 312, which will be described below. The distal end 313 is secured to and supports the top 3 06 and side wall 307 of the ink jet nozzle. In use, the ink is supplied into the nozzle chamber through passage 302 and opening 3 3 in any suitable manner, but is generally as described in the prior patent application. When it is desired to eject ink droplets from the nozzle chamber, current is supplied to the bending actuator 310, causing the actuator to flex to the position shown in Figure 6 and moving the top 306 downward toward the bottom 305. This relative motion reduces the deposition of the nozzle chamber such that the ink projects upward through the nozzle edge 3 09 (Fig. 6) as shown at 314, which forms a droplet by the surface tension in the ink. When the current is withdrawn from the bending actuator 310, the actuator returns to the straight configuration as shown in Figure 7, moving the top 306 of the nozzle chamber up to its original position. The momentum that partially forms the ink droplets causes the droplets to continue to move upwardly, forming an ink droplet as shown in Figure 7, which is projected onto an adjacent paper surface or other item to be printed. In one form of the invention, the opening 303 in the bottom 305 is relatively large compared to the cross section of the nozzle chamber. When the top portion 3 06 moves downward, the viscous tension in the supply tube through the hole in the side wall of the hole 306 and from the ink reservoir (not connected) to the opening - 21 · 200824914 (19) ^ 302 The ink droplets are ejected through the nozzle edge - 309. In order to prevent ink from leaking from the nozzle chamber during actuation (i.e., during bending of the bending actuator 310), a fluid seal is formed between the side walls 307 and 308, as will now be described with reference to Figures 7 and 8. By. During the relative movement of the top 306 and the bottom plate 305, the ink is retained in the nozzle chamber by ensuring that the ink is held in the geometry of the ink chamber with surface tension. For this purpose, a very small gap is provided between the downwardly extending side wall 307 and the mutually facing surfaces 316 of the side walls 308 extending. As can be clearly seen in Figure 8, by the proximity of the two side walls, the ink (showing as a black shaded area) is confined within the aperture between the downwardly extending side wall 307 and the inwardly facing surface of the upwardly extending side wall 31. The proximity of the two side walls ensures that the ink of the entire free opening 31 is "self-sealing" by the surface tension. In order to prevent the possibility of damaging the surface tension by impurities or other factors that may damage the surface tension, the side wall 308 extending upwardly φ is provided in such a manner as to face the upper channel, the channel having not only the inner surface 3 16 but also the spacing Parallel outer surface 3 1 8 and a U-shaped channel 3 1 9 is formed between the two surfaces. The ink droplets that have detached from the surface tension between the surfaces 3 07 and 3 16 overflow into the U-shaped channel. The overflowed ink is held in the channel instead of "wicking" to the entire surface of the nozzle bottom. In this way, a double wall fluid seal is formed and it is capable of efficiently holding the ink within the moving nozzle mechanism. Referring to Figure 8, it can be seen that the actuator 310 includes a first active beam 3 58 disposed above and spaced apart from the second passive beam 360. By separating the two beams, heat transfer from the active beam 358 to the passive beam 360 can be minimized. Therefore, this -22-200824914 (20) compartment configuration has the advantage of maximizing thermoelastic efficiency. In the present invention, the active beam 2 58 may comprise an aluminum alloy, as described above, such as an aluminum vanadium alloy. Thermal Bending Actuator Defining the Top of the Moving Nozzle The embodiment illustrated in Figures 5-8 shows a nozzle assembly 3 00 that includes a nozzle chamber 304 having a top portion 306 that moves relative to the bottom portion 305 of the chamber. The movable top 306 is actuated to move toward the bottom 305 by a double layer thermal bending actuator 310 disposed outside of the nozzle chamber 305. Since only one side of the motion structure must work against viscous ink, the top of the motion reduces the droplet ejection energy. However, it is necessary to increase the amount of power that the droplets emit. By increasing the amount of power, a shorter pulse width can be used to provide the same amount of energy. Improved droplet ejection characteristics are obtained by a shorter pulse width. One means of increasing the power of the actuator is to increase the size of the actuator. However, in the nozzle design shown in Figures 5-8, increasing the size of the actuator obviously adversely affects the space of the nozzle, which is undesirable for making high resolution page wide print heads. The nozzle assembly 400 shown in Figures 9-1 2 provides a solution to this problem. The nozzle assembly 400 includes a nozzle chamber 401 formed on a passive metal oxy-compound (CMOS) layer 402 of the ruthenium substrate 403. The nozzle chamber is defined by a top portion 404 and a side wall 405 extending from the top to the passive gold-oxygen complementary semiconductor layer 402. The ink is supplied to the nozzle chamber 401 by the ink inlet 406 in fluid communication with the ink supply channel 407. The ink supply channel 407 receives ink from the back side of the substrate. The ink is ejected from the nozzle chamber by the jet -23-200824914 (21) - nozzle opening 408 defined in the top 4〇4. The nozzle opening 408 is offset relative to the ink inlet 406. As shown more clearly in Figure 10, the top portion 404 has a moving portion 409 that defines a substantial portion of the entire area of the top portion. The motion portion 409 generally defines at least 20%, at least 30%, at least 40%, or at least 50% of the total area of the top portion 404. In the embodiment illustrated in Figures 9-1 2, nozzle opening 408 and nozzle edge 41 5 are defined in moving portion 409 such that nozzle opening 408 and nozzle edge 415 move with moving portion 409. The nozzle assembly 400 is characterized in that the moving portion is defined by a thermal bending actuator 410 having a flat upper active beam 41 and a flat lower passive beam 412. Thus, actuator 410 generally defines at least 20°/ of the entire area of top portion 404. At least 30%, at least 4%, or at least 50%. Correspondingly, the upper active beam 411 generally defines at least 20%, at least 30%, at least 40%, or at least 50% of the total area of the top portion 404. As shown in Figures 9 and 10, at least a portion of the upper active beam 41 1 and the lower passive beam 0 412 are spaced apart to maximize thermal insulation of the two beams. More specifically, the titanium layer is used as the bridge level 413 between the upper active layer 411 (containing titanium nitride) and the lower passive layer 412 (containing cerium oxide). This gap 41 4 improves the overall efficiency of the actuator 410 by minimizing heat transfer from the active layer 411 to the passive layer 41 2 . However, it will of course be appreciated that in another embodiment, the active beam 411 can be directly fused or bonded to the passive beam 4 1 2 to improve structural rigidity. This design modification is still within the scope of the art and is included in the scope of the invention - 24 - 200824914 (22) ' With the titanium bridge layer, the active beam 4 1 1 is connected to a pair of contacts 4 1 6 (positive ^ and ground) The contact is connected to the driving circuit in the MOS layer. When it is required to eject ink droplets from the nozzle chamber 401, a current flows between the two contacts 4 16 to obtain the active beam 411. The active beam 411 is rapidly heated by the current' and expands relative to the passive beam 412, thereby causing the actuator 41 0 (which defines the moving portion 409 of the top portion 404) to bend downward toward the substrate 403. The movement of the actuator 401 causes the ink to be ejected from the nozzle opening 408 by rapidly increasing the pressure inside the nozzle chamber 40 1 . When the current stops flowing, the moving portion 409 of the top portion 404 is allowed to return to its rest position, which draws ink from the inlet 406 into the nozzle chamber 401 to prepare for the next injection. Therefore, the principle of droplet ejection is similar to that described above with respect to nozzle assembly 300. However, due to the thermal bending actuator 410 defining the moving portion 409 of the top portion 404, a greater amount of power is available for droplet ejection because the active beam 411 has a larger area than the overall size of the nozzle assembly 400. φ Referring to Figure 12, it can be appreciated that the nozzle assembly 40 (and all of the nozzle assemblies described herein) can be replicated into an array of nozzle assemblies to define a print head or a circuit-integrated print head. The integrated print head includes a ruthenium substrate, an array nozzle assembly formed on the substrate (usually arranged in a row), and a drive circuit for the nozzle assembly. A plurality of integrated circuit-integrated printheads may be contiguous or connected to form a pagewidth inkjet printhead, as described, for example, in the applicant's earlier U.S. Patent Application No. 1/0,449, filed on Serial No. 1 0/014732 (2004/1 2/20 application) as described in the application. The contents of these applications are hereby incorporated by reference. -25- 200824914 (23) A nozzle assembly 500 shown in Figs. 13 to 15 is similar to the nozzle assembly 400. - A thermal bending actuator 5i0 having an upper active beam 5 1 1 and a lower passive beam 5 1 2 defining a moving portion of the top 504 of the nozzle chamber 501. Therefore, the nozzle assembly 500 achieves the same advantages as the nozzle assembly 400 in terms of increased power. However, in contrast to nozzle assembly 400, nozzle opening 508 and edge 515 are not defined by the moving portion of top portion 504, but rather by the fixed portion of top portion 504 such that during ejection of the droplet, actuator 5 1 0 moves independently of the nozzle opening and edge. The advantage of this structure is that it provides easier control of the direction of flight of the droplets. It is of course understood that the aluminum alloy (due to its inherent advantages in improving the thermal bending efficiency) can be used as the active beam of either of the thermal bending actuators 410 and 5 10 described above with respect to the embodiment shown in Figures 9 - 15. The nozzle assemblies 400 and 500 can be constructed in a manner similar to that of the applicant's earlier inkjet nozzle manufacturing methods of U.S. Patent Nos. 606,167 and 6,788,809, using suitable microelectromechanical techniques. The contents of φ of these patent cases are hereby incorporated by reference. Active Beam with Optimal Stiffness in the Bending Direction Referring now to Figures 11-15, it can be seen that the upper active beams 4 1 1 , 5 1 1 of the actuators 410 and 510 both contain twisted beam elements that have a bend (at The case of beam 4丨) or serpentine (in the case of beam 5 1 1). The twisted beam element is elongate and has a relatively small cross-sectional area suitable for resisting heating. In addition, the twisted structure allows the ends of the beam members to be connected to the joints at one end of the actuator, simplifying the overall design of the nozzle assembly and the structure of -26-200824914 (24). Referring specifically to Figures 14 and 15, the elongate beam member 520 has a serpentine configuration defining an elongate active cantilever beam 511 of the actuator 510. The serpentine beam 52A has a flat twist path that connects the first electrical contact 51 and the second electrical contact 51. The electrical contacts (positive and ground) are located at one end of the actuator 5 1 , and provide an electrical connection between the drive circuit and the active beam 511 in the gold-oxygen complementary semiconductor layer 502. The serpentine beam element 520 is fabricated from standard lithography etching techniques and is defined by a plurality of contact members. In general, the beam member can be defined as a solid portion of the beam material that extends generally linearly along, e.g., longitudinally or laterally. The beam member of the beam member 520 includes a longer beam member 521 and a shorter beam member 522. The longer beam members 521 extend along the longitudinal axis of the elongate cantilever beam 51 1 and the shorter beam members 522 extend across the transverse axis of the elongate cantilever beam 51 1 . An advantage of this serpentine beam element 520 structure is that it provides maximum stiffness of the cantilever beam 511 in the direction of bending. The stiffness in the direction of the bend is advantageous because it facilitates the bending of the actuator 5 10 back to its rest position after each actuation, and the curved active beam structure for the nozzle assembly 400 shown in Figure 11 should be understood. The same or similar advantages as described above with respect to the structure of the nozzle assembly 500. In Fig. 11, the longitudinally extending longer beam members are shown as 421' and the laterally extending interconnected shorter beam members are shown as 422. Use of a porous material to improve thermal efficiency. In all of the above embodiments, and other thermal bending actuators described in the Applicant's application, the active beam is bonded to the passive beam for construction. - Ruggedness (see Figures 1 and 2), or the active and passive beams are spaced apart for maximum thermal efficiency (see Figure 8). The thermal efficiency provided by the air gap between the beams is of course desirable. However, this improvement in thermal efficiency is often at the expense of structural robustness and the tendency to buck the thermal bending actuator. U.S. Pat. β The material is formed by depositing niobium carbide or oxidizing a carbon component to form porous ceria. The porosity of the produced porous cerium oxide can be increased by increasing the ratio of carbon to cerium. Porous ceria is known to be used as a passivation layer in integrated circuits to reduce parasitic impedance. However, applicants of this type have discovered that this type of multi-material can be used to improve the efficiency of thermal bending actuators. The porous material can be used as an insulating layer between the active beam and the passive beam, or as a passive beam itself. φ Figure 16 shows a thermal bending actuator 600 comprising an upper active beam 601, a lower passive beam 602, and an insulating layer 6〇3 between the upper active beam and the lower passive beam. The insulating beam comprises porous ceria, and the active beam 601 and the passive beam 6〇2 may comprise any suitable material, such as titanium nitride and ceria, respectively. The porosity of the insulating layer 603 provides excellent thermal insulation between the active beam 601 and the passive beam 6〇2. The insulating layer 6 〇 3 also provides an actuator 650 having a structural robustness. Thus, the actuator 6 is combined with the advantages of the two types of thermal bending actuators described in relation to Figures 1, 2, and 8 above. In another embodiment, and as shown in Figure 7, the porous material can be simply formed into a passive layer of a double-layer thermal bending actuator -28 - 200824914 (26). Thus, the thermal bending actuator 650 includes an upper active beam 651 (which includes titanium nitride), and a lower passive beam 652 (which includes porous ceria). It will of course be appreciated that the thermal bending actuator of the type illustrated in Figures 16 and 17 can be incorporated into any suitable ink jet nozzle or other micro-mechanical mechanical system device. Improvements in thermal efficiency and structural rigidity have made such actuators attractive in any micro-electromechanical system application requiring mechanical actuators or transducers. The thermal bending actuator of the type shown in Figures 16 and 17 is particularly suitable for use in the above described ink jet nozzle assemblies 400, 500. Those skilled in the art will appreciate that appropriate modifications of the thermal bending actuators 410, 510 can achieve the above improvements in thermal efficiency and structural rigidity. It will be appreciated that the active beam members 61, 65 1 of the thermal bending actuators 600, 650 described above may comprise an aluminum alloy as described herein to further improve thermal bending efficiency. It is to be understood that the invention is described by way of example only, and the details of the invention BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic side view of a two-layer thermal bending actuator comprising an active beam formed of an aluminum-vanadium alloy; Figures 2(A)-(C) are schematic illustrations of an inkjet nozzle assembly Side cross-sectional view including the operation of a fused thermal bending actuator at various stages; 29- 200824914 (27) Figure 3 is a perspective view of the nozzle assembly shown in Figure 2(A); Figure 4 is a portion incorporating the circuit A perspective view of a printhead comprising a nozzle assembly as shown in Figures 2(A) and 3; Figure 5 is an exploded perspective view of the inkjet nozzle assembly including spaced apart thermal bending Figure 6 is a cut-away perspective view of the ink jet nozzle assembly of Figure 5 in an actuated configuration; Figure 7 is an exploded perspective view of the ink jet nozzle assembly of Figure 5 when it is just activated Figure 8 is a side cross-sectional view of the ink jet nozzle assembly of Figure 6; Figure 9 is a side cross-sectional view of the ink jet nozzle assembly including a top portion having a moving portion defined by a thermal bending actuator; 10 is an excised perspective view of the nozzle assembly shown in FIG. 9; FIG. 11 is a perspective view of the nozzle assembly shown in FIG. Figure 1 is an exploded perspective view of the array nozzle assembly of Figure 10; Figure 13 is a side cross-sectional view of another embodiment of the ink jet nozzle assembly including a top portion having a thermal bending actuator Figure 14 is an exploded perspective view of the nozzle assembly of Figure 13; Figure 15 is a perspective view of the nozzle assembly of Figure 13; Figure 16 is a schematic representation of a three-layer thermal bending actuator A side view comprising an insulating beam formed of a porous material sandwiched therebetween; and Figure 17 is a schematic side view of a three layer thermal bending actuator comprising a passive beam formed of a porous material. -30- 200824914 (28) ^ [Explanation of main component symbols] . 1 : (nozzle) chamber 2 : passivation layer 3 : (矽) substrate 4 : top 5 : side wall 6 : ink 7 : (ink inlet) channel 8 : (nozzle) opening 9 : blade 1 〇 : actuator 1 1 : arm 12 : slot 1 3 : actuator unit 1 4 : fixed column 0 15 : (first) active beam 16 : (second) passive beam 17: (ink) droplet 20: (ink) meniscus 21: edge 100: nozzle assembly 200: (thermal bending) actuator 201: cantilever beam 202: column 200824914 (29) 2 10: 220: 3 00 : 3 01 : 3 02 : 3 03 : 3 04 : 3 05 :
3 06 ： 3 07 ： 3 08 ： 3 09 ： 3 10： 3 11： 3 12：3 06 : 3 07 : 3 08 : 3 09 : 3 10: 3 11: 3 12:
3 14 3 15 3 16 3 16 3 17 3 18 3 19 (下）主動樑 (上）被動樑 噴嘴組合體 基板 通道（（墨水供給）孔） 開口（入口） 腔室 底部 頂部 側壁 側壁 (噴嘴）邊緣 (彎曲）致動器 近端 錨構件 遠端 突出 (墨水）液滴 (相互面對的）表面 (向）內表面 自由開口 外表面 =槽道 3 5 8 :主動樑 200824914 (30) 3 60 ： 400 ： 401 ： 4 02 ： 403 ： 404 ： 4 06 ： 407 ：3 14 3 15 3 16 3 16 3 17 3 18 3 19 (bottom) active beam (top) passive beam nozzle assembly substrate channel ((ink supply) hole) opening (inlet) chamber bottom top side wall (nozzle) edge (bending) actuator proximal anchor member distal projection (ink) droplets (facing each other) surface (toward) inner surface free opening outer surface = channel 3 5 8 : active beam 200824914 (30) 3 60 : 400 : 401 : 4 02 : 403 : 404 : 4 06 : 407 :
408： 408 ： 409 ： 410 ： 411： 412 ： 413 ： 414 ： 415 ： 416 ： 421 ： 422 ： 501 502 504 508 被動樑 噴嘴組合體 (噴嘴）腔室 (鈍態）金氧互補半導體層 (矽）基板 頂部 (墨水）入口 (墨水供給）槽道 (噴嘴）開口 (噴嘴）開口 運動部 (熱彎曲）致動器 (上）主動樑 (下）被動樑 橋接層 間隙 (噴嘴）邊緣 接點 較長的樑構件 較短的樑構件 (噴嘴）腔室 金氧互補半導體層 頂部 (噴嘴）開口 -33 200824914 (31) 510 ： 5 11： 5 11： 512 ： 5 15 ： 5 16 ： 520 ： 521 ：408: 408 : 409 : 410 : 411 : 412 : 413 : 414 : 415 : 416 : 421 : 422 : 501 502 504 508 Passive beam nozzle assembly (nozzle) chamber (passive) gold-oxygen complementary semiconductor layer (矽) Substrate top (ink) inlet (ink supply) channel (nozzle) opening (nozzle) opening moving part (hot bending) actuator (top) active beam (lower) passive beam bridge layer gap (nozzle) edge contact longer Beam member shorter beam member (nozzle) chamber oxy-complementary semiconductor layer top (nozzle) opening -33 200824914 (31) 510 : 5 11: 5 11: 512 : 5 15 : 5 16 : 520 : 521 :
5 22 ： 600 ： 601 : 602 ： 603 ： 650 65 1 652 (熱彎曲）致動器 (上）主動樑 主動懸臂樑 (下）被動樑 邊緣 (第一、第二）電性接點 樑元件 較長的樑構件 較短的樑構件 (熱彎曲）致動器 (上）主動樑 (下）被動樑 絕緣層 (熱彎曲）致動器 (上）主動樑 (下）被動樑5 22 : 600 : 601 : 602 : 603 : 650 65 1 652 (hot bending) actuator (top) active beam active cantilever beam (lower) passive beam edge (first, second) electrical contact beam components Long beam members shorter beam members (hot bending) actuators (top) active beams (lower) passive beam insulation (thermal bending) actuators (top) active beams (lower) passive beams