A kind of friction generator
Background technology
Adopt the collection of energy of nanometer technology and conversion equipment due to the self power generation of its uniqueness and self-driven character, probably in manufacture and driving self-powered nano-device and nanosystems device, play critical effect, receive various countries researcher recently and more and more pay close attention to.2006, georgia ,u.s.a Institute of Technology Wang Zhonglin taught seminar and successfully achieves the piezoelectric type nano generator utilizing zinc oxide nanowire changes mechanical energy to be become electric energy first.Subsequently, based on piezoelectric effect, the various nano generators based on different materials and structure are developed in succession.At present, the power output of nano generator is enough to drive commercial light-emitting diode (LED), small liquid crystal display, even self-power wireless data transfer equipment.Power density also reaches 1-10mW/cm
3.
Generally, generator is that one can generate electric charge, is separated by positive and negative charge, and drives the method for free electron stream with the electric charge that electromotive force produces, and it can based on electromagnetism, piezoelectricity, thermoelectricity, even electrostatic effect.The piezoelectricity electromotive force that nano generator relies on zinc oxide nanowire to generate achieves generating.On the other hand, friction electricity and electrostatic phenomenon are a kind of very general phenomenons, being present in every aspect in our daily life, driving etc. from walking to.Because it is difficult to be collected and utilize, often a kind of energy form of ignoring by people.If we can collect fricative electric energy by a kind of new method or utilize the method that kinetic energy irregular in daily life is changed into the electric energy that can utilize, produce material impact by our daily life.By the end of so far, static micro generator is developed successfully, and is used widely in micro electronmechanical (MEMS) field.But the design of miniature electrostatic generator is mainly based on inorganic silicon material, and the manufacture of device needs complicated technique and accurate operation.The preparation of whole device needs large-scale instrument and equipment and special working condition, and cost is too high, is unfavorable for commercialization and the daily use of generator.Chinese Patent Application No. is 200910080638.X, disclose a kind of revolving frictional generator, this generator utilizes frictional electricity phenomenon to generate electricity, the friction material on stator of outer casing inner wall contacts with the friction rotor material tight of armature spindle drum outer wall, by rotor beam barrel, make friction material on stator and the spin friction of friction rotor storeroom, generation current, and drawn by rotor output.But this revolving frictional generator needs specific mechanical energy to drive, can not be used for collecting and changing irregular kinetic energy, as motion and the unordered wind energy etc. of human muscle's part, and this device generating efficiency is not high.
Summary of the invention
The present invention solves the problems of the prior art to provide the friction generator that a kind of applied environment is wider, generating efficiency is higher.
The invention provides a kind of friction generator, comprise the first electrode and the second electrode, described first electrode comprises the first high molecular polymer insulating barrier, and described first high molecular polymer insulating barrier one side surface is micron order concaveconvex structure, and opposite side surface is provided with metallic film; Described second electrode comprises the second high molecular polymer insulating barrier, and described second high molecular polymer insulating barrier one side surface is micron order concaveconvex structure, and opposite side surface is provided with metallic film; The surface of described first electrode micron order concaveconvex structure is just fixedly connected with pasting merga pass outer ledge with the surface of the second electrode micron order concaveconvex structure; Described micron order concaveconvex structure is formed by polishing process; Metallic film on the metallic film of described first high molecular polymer insulating barrier and the second high molecular polymer insulating barrier is the voltage and current output electrode of friction generator.
The present invention also provides a kind of triboelectricity unit, is undertaken connecting or composing in parallel by monomer friction generator of the present invention, to improve the power output of output current or unit are.
Described high molecular polymer insulating barrier of the present invention is selected from polyimide film, aniline-formaldehyde resin film, polyformaldehyde film, ethyl cellulose film, polyamide film, melamino-formaldehyde film, polyethylene glycol succinate film, cellophane, cellulose acetate film, polyethylene glycol adipate film, polydiallyl phthalate film, fiber sponge film, regeneration sponge films, elastic polyurethane body thin film, styrene-acrylonitrile copolymer copolymer film, styrene-butadiene-copolymer film, staple fibre film, poly-methyl film, methacrylic acid ester film, polyvinyl alcohol film, polyester film, polyisobutene film, polyurethane flexible sponge films, pet film, polyvinyl butyral film, formaldehyde-phenol film, neoprene film, butadiene-propylene copolymer film, natural rubber films, polyacrylonitrile film, one in acrylonitrile vinyl chloride film and polyethylene third diphenol carbonate thin film, but described first high molecular polymer insulating barrier is different from described second high molecular polymer insulating barrier material.If the first high molecular polymer insulating barrier of the first electrode is identical with the second high molecular polymer insulating barrier material of the second electrode, the quantity of electric charge of triboelectrification can be caused very little.
Described first electrode and the second electrode are configured to by making its arbitrarily bending, distortion and produce the flexible flat structure of described electrode triboelectrification.Flexible flat structure can expand the applied environment of friction generator, collects and change irregular kinetic energy, as motion and the unordered wind energy etc. of human muscle's part.
The micron order concaveconvex structure of described first high molecular polymer insulating barrier and the second high molecular polymer surface of insulating layer is minute unevenness structure.
Described first electrode can be connected by modes such as adhesive tapes with the outer ledge of the second electrode.
Metallic film on described first high molecular polymer insulating barrier and the second high molecular polymer insulating barrier is all plated on surface of insulating layer by vacuum sputtering or vapour deposition method.Described metallic film can be the material of any one conduction, as transparent conductive film, conducting polymer, stainless steel etc.; Be preferably the one in gold, silver, platinum, aluminium, nickel, copper, titanium, chromium, tin and alloy thereof, thickness is preferably 50nm-200nm.
Friction electric generator provided by the invention relies on the charge pump effect of friction electromotive force, this kind of method being simple, low cost and can be mass-produced.Based on double-decker, electricity exports and reaches crest voltage 3.3V, electric current 0.6 μ A, peak power density 10.4mW/cm
3.Compared with other miniature energy collection method existing, friction electric generator of the present invention has the advantage of following uniqueness.First, this is a kind of novel electricity generator based on the principle of novelty and method, and it is possibly for the investigation and application of organic electronic device and flexible electronic opens up new research field; Secondly, the manufacturing process of whole device does not need expensive raw material and advanced manufacturing equipment, and this will be conducive to its large-scale industrial production and practical application.Finally, this device, based on flexible polymer sheet, is easily processed, the long service life of device, and easily and other processing technology integrated.Friction electric generator shows its good application prospect, energy can be obtained from numerous irregular activities such as mankind's activity, tyre rotation, wave, mechanical oscillation, can be personal electric product, environmental monitoring, medical science etc. and self-powered and self-propelling device are provided, have huge commercialization and practical potentiality.
Accompanying drawing explanation
Fig. 1 is the structural representation of friction generator of the present invention.
Fig. 2 is the micron order concaveconvex structure schematic diagram of the surface of insulating layer of friction generator of the present invention.
Fig. 3 is the power generation process change in electrical charge schematic diagram of friction generator of the present invention.
In figure: 1-metallic film, 2-first high molecular polymer insulating barrier, 3-second high molecular polymer insulating barrier, the micron order concaveconvex structure of 4-surface of insulating layer.
Embodiment
Below, by reference to the accompanying drawings the specific embodiment of the present invention is described further.
Accompanying drawing 1 represents the typical structure of a friction generator based on high molecular polymer.Friction generator is just as a sandwich structure be made up of two kinds of different polymer sheets, and two polymer sheets are stacked each other on together, and interlayer is without any binding.As shown in Figure 1, (4.5cm × 1.2cm) polyimide film (thickness 125 μm of a rectangle, Du Pont 500HN, Kapton in accompanying drawing 3) as the high molecular polymer insulating barrier 4 of the first electrode, be placed in the second high molecular polymer insulating barrier 2 flexible mylar substrate (thickness 220 μm, PET in accompanying drawing 3).The edge that two of this device are short seals with common adhesive plaster, ensures the appropriateness contact of two polymer insulation layer.Two surfaces of this structural top and bottom are coated with alloy metal film 1 (thickness 100nm, Au in accompanying drawing 3) by the method for sputter coating and make electrode.Metallic film plays two important function here: (1) can respond to two high polymer sheet boundary zones due to fricative potential change, generates equivalent but electrically contrary dislocation charge; (2) positive and negative electrode as generator is directly connected with external circuit, is the output electrode of the voltage and current of friction generator.The whole preparation technology of this device is simple, can large-scale production.Therefore, the present invention can realize under the condition of lower cost, less raw material and manufacturing procedure.
As shown in Figure 2, flexible polyimide film and the surface of mylar substrate have micron order concaveconvex structure 4, and this micron order concaveconvex structure 4 can increase frictional resistance, improves generating efficiency.Described micron order concaveconvex structure 4 directly can be formed when film preparation, also the surface of high molecular polymer film can be made to form irregular micron order concaveconvex structure by the method for polishing.
Fig. 3 is the diagram of friction generator electricity generating principle.When External Force Acting is on device, two biopolymer layer produce deformation, and contact with each other in the region at interface and rub.External force mechanism makes two polymeric layer generation relative slidings.The low degree result caused that rubs is, due to the existence of two polymer film surface roughness, equivalent but electrically contrary electrostatic charge generate in interface and are distributed on two different polymer film surfaces, polyester film surface is mainly positively charged, and polyimide film surface is mainly electronegative, so just define the dipole layer that is referred to as friction potential in interface.And this dipole layer just forms a built-in potential between two planar metal pole plates.Because polymer film itself is insulation, so induced charge can not be led away rapidly or is neutralized.Generate impact on whole system to offset built-in potential, metal polar plate will induce electrically contrary free charge respectively, and the free charge sensed outside circuit turn-on when will neutralize, by load and then formation extrinsic current.When External Force Acting disappears, two polymer films return to formation state by case of bending, in this process, relative sliding and friction occur again, and dipole layer changes due to the neutralization of interface electric charge, and built-in potential changes simultaneously.The change of built-in potential will cause two metal polar plates to be responded to again, produce and the antipodal free charge of case of bending.When free charge flows through external circuit load, again form the extrinsic current contrary with in bending situation.By repeatedly rubbing and recovering, just periodic ac signal can be formed in external circuit.
Describe in further detail the power generation process in Fig. 3, the first step is friction process, produces local electric charge at interface zone, forms built-in potential.Second step is induction process, when device produces mechanical deformation, the distance between two metal polar plates changes, and causes the change of interior electric capacity and the generation of built-in potential, and then the redistribution of two metal polar plate generation free charges can be caused, form extrinsic current when free charge flows through external circuit load.Only have the movement and generation current that when to have electrical potential difference when between two electrodes, just can form free charge, and electrical potential difference causes just because of triboelectrification effect.3rd step is N-process, when disappearing to applied external force, two high-polymer membranes return to original state.The spacing of two metal polar plates returns to original state, and interior electric capacity changes again, and built-in potential weakens due to the mutual neutralization of electric charge or disappears.Two metal polar plates before having reached electric potential balancing produce electrical potential difference again.4th step is recovery process, and free charge flows through external circuit under the driving of electrical potential difference, forms electric current, until the electromotive force of two metal polar plates is equal.Form the foreign current contrary with electrical symbol during device deformation in this process.Whole process is exactly the process of the friction electric generator output AC signal of telecommunication.Finally, generator is when frictional force is removed, and two high-polymer membranes will recover their original shape, and CHARGE DISTRIBUTION also returns to reset condition.Whole power generation process is see accompanying drawing 3.
In the present embodiment, be the performance of characterize polymers friction electric generator, the electric property of this device is characterized.Due to the existence of polymer insulation layer between two metal electrodes, this device reveals typical open circuit feature at the meter of I-V (current-voltage).The stepping motor of life cycle vibration (tension force of 0.33Hz and 0.13%) makes the bending of friction electric generator generating period and release, maximum output voltage and the current signal of friction electric generator reach 3.3V and 0.6 μ A respectively, and peak power output density reaches 10.4mW/cm
3.
Friction generator of the present invention meets the linear superposition theorem that basic circuit connects, when namely no matter being connected to measurement mechanism forward or backwards, total output current can be enhanced (equidirectional) in the mode of devices in parallel or reduce (contrary direction).Thus can by the mode of the multiple friction electric generator of parallel connection, and Multilayer generator can be assembled due to the panel construction that friction electric generator is thin simultaneously, increase output current with this.Certainly, also triboelectricity unit can be formed, to improve the power output of unit are by the multiple friction electric generator of series connection.
Above, invention demonstrates a method and a kind ofly utilize rubbing action to obtain the innovation of energy and effective method.Friction electric generator relies on the inductive effect of the internal friction electrification change of electromotive force and both sides metal polar plate to produce electric energy, and it is a kind of method of simple, efficient and low cost.
The present invention is not limited to above-mentioned execution mode, and when not deviating from flesh and blood of the present invention, any distortion that those skilled in the art can expect, improvement, replacement all fall into scope of the present invention.