Three-electrode linear and bending polymeric actuator

{
  "publication_number": "US2013093287A1",
  "country": "US",
  "kind": "A1",
  "title": "Three-electrode linear and bending polymeric actuator",
  "abstract": "A polymeric actuator includes a first and a second electrode layer (2, 3), both containing electrically conductive material and able to change size in at least one direction of deformation under the action of charge injection or ion intercalation. A solid polymer electrolyte layer (4) is interposed between the first and the second electrode layer, in which the solid polymer electrolyte layer is electrically insulating and ionically conductive. The actuator is able to deform by the action of the dimensional changes of the first and second electrode layer. The actuator further includes a passive electrode (5) immersed in the solid electrolyte layer to be electrically insulated relative to the first and second electrode layer, in which the passive electrode is electrically conductive and elastically deformable material, so as to support mechanically the deformations of the actuator induced by the dimensional changes of the first and second electrode layer.",
  "claims": [
    "1. A polymeric actuator comprising a first and a second electrode layer (2, 3), both containing an electrically conductive material and able to change size along at least one direction of deformation as a result of charge injection or ion intercalation, and a solid polymer electrolyte layer (4) interposed between said first and the second electrode layers, where said solid polymer electrolyte layer is an electrical insulator and a ionic conductor, where said actuator is able to alter its shape as a result of dimensional changes of the said first and second electrode layers, characterized in that said actuator comprises a passive electrode (5) immersed in the solid polymer electrolyte layer in order to be electrically insulated with respect to the said first and second electrode layers, where the said passive electrode is made of electrically conductive and elastically deformable material, in order to mechanically comply with deformations of the actuator induced by the dimensional changes of the said first and second electrode layers, where said actuator has the ability of assuming different deformation configurations in response to corresponding polarization configurations of the said first and second electrode layers and of the passive electrode. 2. Actuator according to claim 1, wherein the deformation configurations comprise linear motion, bending and combination of linear motion and bending. 3. Actuator according to claims 1 and 2, wherein the said first and second electrode layers are composed of a material selected from the group consisting of: multi walled carbon nanotubes (MWCNT), double walled carbon nanotubes (DWCNT), or single walled carbon nanotubes (SWCNT), chemically modified carbon nanotubes, also in the form of buckypaper, bucky gel, or graphene, graphite, carbon black or the aforementioned materials in the form of composites with polymers; carbide derived carbon composites, intrinsecally conductive polymers like polypyrrole (PPy), polyaniline (PANI), poly(3,4-ethylenedioxythiophene) (PEDOT), poly (3-methylthiphene) (pMeT), porous metal electrodes. 4. Actuator according to any of the claims from 1 to 3, wherein the said solid polymer electrolyte layer is composed of at least one ionic conductive polymer or of a mixture of at least one polymer and one salt. 5. Actuator according to claim 4, wherein the ionic conductive polymer of the solid polymer electrolyte layer is selected from the group consisting of: Nafion®, Flemion®, sulfonated poly(ether ether ketone)(SPEEK), sulfonated polysulfones and other sulfonated polymers or anyhow carrying moieties able to exchange ions. 6. Actuator according to claim 4, wherein the polymer for the solid polymer electrolyte, which needs to be mixed with a salt in order to be ionic conductive, is selected from the group consisting of: polyvinylidene fluoride (PVdF), poly(vinylidene fluoride-co-hexafluoropropene) (P(VdF-HFP), poly(vinylidene fluoride-tetrafluoroethylene) (P(VdF-TFE)), poly(vinylidene fluoride-trifluoroethylene) (P(VdF-TrFE)), poly(methyl methacrylate) (PMMA), polyvinyl chloride (PVC), poly acrylic nitrile (PAN), mixtures PVC/PAN, poly(2-hydroxyethyl methacrylate) (PHEMA), polyethylene oxide (PEO) and polymers based on styrene/divinylbenzene. 7. Actuator according to claim 4 or 6, wherein the salt of the solid polymer electrolyte layer is an ionic liquid based on imidazolium, piperidinium, pyrrolidinium and quaternary ammonium salts. 8. Actuator according to any of the previous claims, wherein the said first and second electrode layers are made of 0-50% in weight of ionic liquid, 0-50% in weight of polymer and the remaining portion in weight of active material for the electrode, and wherein the said solid polymer electrolyte layer is composed of an ionic liquid and at least a polymer, with a weight proportion in ionic liquid/polymer from 10:1 to 1:10 or anyhow such that it may reach an ionic conductivity value of at least 10 −6 S/cm. 9. Actuator according to any of the previous claims, wherein the said passive electrode is selected from the group consisting of helical or spiral metallic springs, carbon coated helical or spiral metallic springs; conductive elastomers, Lycra® conductive fibres, ionically doped conductive polymers; metal ions implanted in the solid polymer electrolyte layer. 10. Actuator according to any of the previous claims, which comprises a plurality of the said passive electrodes placed side by side and immersed into the solid polymer' electrolyte layer in order as to be electrically insulated between each other and with respect to the said first and second electrode layers. 11. Actuator according to claim 10, which comprises also a plurality of the said first electrode layers placed side by side and/or a plurality of the said second electrode layers placed side by side, which are placed so as to be electrically insulated between each other."
  ],
  "description_excerpt": "The present invention relates to a polymeric actuator, comprising\n\nActuators able to generate force and displacement in response to an electrical signal are currently in use in various sectors of industry and the performance requirements are tending to be more and more diverse. A great many technologically advanced applications require actuators that are light, compact and actuated at low voltages. Moreover, it is important for said actuators to be able to effect movements easily in different directions, and moreover to be safe and easy to manipulate.\n\nThere has recently been increasing interest in organic actuators that can be deformed by an electrical signal. Many of said actuators are light and are able to operate in a gaseous environment, for example in the atmosphere. An example of said actuators is described in U.S. Pat. No. 7,315,106, which relates to an actuator of the type defined at the beginning. This actuator is composed of carbon nanotubes, a non-volatile ionic liquid and a polymer. Although this type of actuator is simple to manipulate and can be used in a gaseous environment, its laminar shape limits its directions of bending, as is described in U.S. Pat. No. 7,449,818.\n\nPolymeric actuators with a tubular geometry have recently been reported. “High performance conducting polymer actuators utilizing a tubular geometry and helical wire interconnects” [1] describes a tubular electromechanical actuator based on polypyrrole with helical wire interconnects.",
  "cpc": [
    "H10N 30/202",
    "B82Y 15/00",
    "F03G 7/0121",
    "F03G 7/029",
    "H01L 41/09",
    "H01L 41/0906",
    "H01L 41/0926",
    "H01L 41/0986",
    "H01L 41/193",
    "H10N 30/20",
    "H10N 30/204",
    "H10N 30/206",
    "H10N 30/857"
  ],
  "ipc": [
    "H10N 30/00",
    "H10N 30/20",
    "H10N 30/857",
    "F03G 7/00"
  ],
  "assignees": [
    "Fondazione Istituto Italiano di Tecnologia"
  ],
  "inventors": [
    "Maurizio Biso",
    "Alberto Ansaldo",
    "Davide Ricci",
    "Giulio Sandini"
  ],
  "filing_date": "2011-06-24",
  "publication_date": "2013-04-18",
  "priority_date": "2010-06-25",
  "application_number": "US-201113805243-A",
  "family_id": "43269876",
  "cited_by_count": 25,
  "citations": [
    "US7361430B1",
    "US20110121691A1",
    "US20120235545A1",
    "US20120032553A1"
  ]
}