Sri International

University of California

Other

Qibing Pei

Ronald E Pelrine

Roy D Kornbluh

Joseph S Eckerle

Marcus Rosenthal

Jose P Joseph

Neville A Bonwit

Scott E Stanford

Jonathan R Heim

Seajin Oh

Richard P Heydt

Zhibin Yu

Ziyang Zhang

Rujun Ma

Yang Yang

Paul Gallagher

Qi Chen

David E Huber

Donald E Czyzyk

Subramanian Venkat Shastri

Yuan Meng

Roy D Kornbluth

Chenjun Shi

Roy David Kornbluh

Marcus A Rosenthal

Richard Heydt

Jospeh S Eckerle

A device comprising one or more heat transfer laminates each including an electrode, a first dielectric layer on a first side of the electrode, and a second dielectric layer on a second side of the electrode; a plurality of flexible electrocaloric elements, each of the flexible electrocaloric elements including an electrocaloric material layer, a flexible electrode layer on the electrocaloric layer, one or more fixed portions each attached to one of heat transfer laminates, and a movable portion that is movable with respect to the one of the heat transfer laminates.

Tandem-structured cooling device driven by electrostatic force

A device including a bottom electrode on a substrate and a top electrode on a substrate separated by a fixed distance from each other. Semi-insulator layers with proper electrical conductivity are attached to the bottom and top electrodes. Disposed between the substrates is a flexible S-shaped polymer stack having electrode layers with one end of the stack attached to the top substrate and the other end in contact with the bottom substrate. When a voltage is applied between the stack and the electrode layer on the bottom substrate, the stack is induced by electrostatic force to deflect in a rolling wave-like motion. While the voltage applied between the stack and bottom electrode is turned off, the static charges on the semi-insulator layer can move away quickly due to the proper electrical conductivity of the semi-insulator layer.

Electrostatically actuated device

A solid-state heat transporting device including a heat transporting element whose uniformity of contact with one or multiple surfaces is controllable so that various amounts of heat may be transported to and from the one or multiple surfaces. The heat transporting element uses the electrocaloric effect to absorb and release the heat and the uniformity of contact is controlled using an electrostatic effect which may change the shape of the heat transporting element. In one embodiment, the heat transporting element is an electrostatically actuated P(VDF-TrFE-CFE) polymer stack achieving a high specific cooling power of 2.8 W/g and a COP of 13 (the highest reported coefficient of performance to date) when used as a cooling device.

Electrocaloric cooling with electrostatic actuation

A method for producing flexible, nanoparticle-polymer composite electrodes is described. Conductive nanoparticles, preferably metal nanowires or nanotubes, are deposited on a smooth surface of a platform to produce a porous conductive layer. A second application of conductive nanoparticles or a mixture of nanoparticles can also be deposited to form a porous conductive layer. The conductive layer is then coated with at least one coating of monomers that is polymerized to form a conductive layer-polymer composite film. Optionally, a protective coating can be applied to the top of the composite film. In one embodiment, the monomer coating includes light transducing particles to reduce the total internal reflection of light through the composite film or pigments that absorb light at one wavelength and re-emit light at a longer wavelength. The resulting composite film has an active side that is smooth with surface height variations of 100 nm or less.

Method for producing nanowire-polymer composite electrodes

A method for the synthesis and use of transparent bulk conjugated polymers prepared from liquid monomers via bulk polymerization. The liquid monomer contains pi-electron conjugated moieties and polymerizable moieties. The monomer solution may also have functionalizing additives such as a luminescence additive that includes organic dyes, luminescent molecules, fluorescent compounds, phosphorescent compounds, and luminescent quantum dots. The monomer solution may also have sensitizing additives such as high-energy photo sensitizing compounds, nanoparticles of compounds containing atoms with atomic numbers greater than 52 and neutron sensitizing additives. The monomer solution is polymerized by heating to an elevated temperature with or without addition of an initiator. Alternatively, the monomer is polymerized by photo-induced polymerization. A photoinitiator may be employed to initiate the photopolymerization. Scintillation materials with significant light yields are illustrated.

Bulk polymer composites

A method for producing high efficiency organic light emitting devices, that have an organic semiconductor active layer sandwiched between electrodes where at least one of the electrodes is a film of conductive nanowires, carbon nanoparticles, light scattering nanoparticles and a polymer support. The light scattering nanoparticles can be incorporated in the conductive nanowires, carbon nanoparticle or polymer support elements of the electrode. The second electrode can be identical to the first to provide a symmetrical device or can be a conductive paste or metal layer. The entire process, including the formation of both of the electrodes, the emissive polymer layer, and the substrate, may be carried out by solution processing.

Method for producing a high efficiency organic light emitting device having a transparent composite electrode comprising a film of conductive nanowires, carbon nanoparticles, light scattering nanoparticles, and a polymer support

The present invention relates to animated devices that include one or more electroactive polymer transducers. When actuated by electrical energy, an electroactive polymer produces mechanical deflection in one or more directions. This deflection may be used to produce motion of a feature included in an animated device. Electroactive polymer transducers offer customizable shapes and deflections. Combining different ways to configure and constrain a polymer, different ways to arrange active areas on a single polymer, different animated device designs, and different polymer orientations, permits a broad range of animated devices that use an electroactive polymer transducer to produce motion. These animated devices find use in a wide range of animated device applications.

Electroactive polymer animated devices

Described herein are transducers and their fabrication. The transducers convert between mechanical and electrical energy. Some transducers of the present invention include a pre-strained polymer. The pre-strain improves the conversion between electrical and mechanical energy. The present invention provides methods for fabricating electromechanical devices including one or more electroactive polymers.

Electroactive polymer manufacturing

The synthesis, characterization, optical and electrochemical properties of a regioregular copolymer, poly(3-octylthiophene-2,5-diyl-co-3-decyloxythiophene-2,5-diyl) (POT-co-DOT), and an alternating regioregular copolymer poly{(9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(3-decyloxythien-2-yl)-2,1,3-benzothiadiazole]-5',5&#x2033;-diyl} (PF-co-DTB) is disclosed. The incorporation of 3-alkoxythiophene units onto the conjugated backbones enhances the electron-donating property of the polymer and lowers its bandgap. The fabrication and performance of photovoltaic cells with bulk heterojunction architecture based on blends of these copolymers with PCBM are also described.

Copolymers of alkoxythiophene

The present invention provides electroactive polymers, transducers and devices that maintain pre-strain in one or more portions of an electroactive polymer. Electroactive polymers described herein may include a pre-strained portion and a stiffened portion configured to maintain pre-strain in the pre-strained portion. One fabrication technique applies pre-strain to a partially cured electroactive polymer. The partially cured polymer is then further cured to stiffen and maintain the pre-strain. In another fabrication technique, a support layer is coupled to the polymer that maintains pre-strain in a portion of an electroactive polymer. Another embodiment of the invention cures a polymer precursor to maintain pre-strain in an electroactive polymer.

Method for forming an electroactive polymer

A bistable electroactive polymer transducer is provided for electrically actuated deformation of rigid electroactive polymer members. The polymers have glass transition temperatures (Tg) above ambient conditions and turn into rubbery elastomers above Tg and have high dielectric breakdown strength in the rubbery state. They can be electrically deformed to various rigid shapes with maximum strain greater than 100% and as high as 400%. The actuation is made bistable by cooling below Tg to preserve the deformation. The dielectric actuation mechanism includes a pair of compliant electrodes in contact with a dielectric elastomer which deforms when a voltage bias is applied between the pair of electrodes. In some of the configurations, the dielectric elastomer is also a shape memory polymer. The deformations of such bistable electroactive polymers can be repeated rapidly for numerous cycles.

Bistable electroactive polymers

The invention describes rolled electroactive polymer devices. The invention also describes employment of these devices in a wide array of applications and methods for their fabrication. A rolled electroactive polymer device converts between electrical and mechanical energy; and includes a rolled electroactive polymer and at least two electrodes to provide the mechanical/electrical energy conversion. Prestrain is typically applied to the polymer. In one embodiment, a rolled electroactive polymer device employs a mechanism, such as a spring, that provides a force to prestrain the polymer. Since prestrain improves mechanical/electrical energy conversion for many electroactive polymers, the mechanism thus improves performance of the rolled electroactive polymer device.

Electroactive polymer device

Method of fabricating an electroactive polymer transducer

Polymerizable anions and/or cations can be used as the ionically conductive species for the formation of a p-i-n junction in conjugated polymer thin films. After the junction is formed, the ions are polymerized in situ, and the junction is locked thereafter. The resulting polymer p-i-n junction diodes could have a high current rectification ratio. Electroluminescence with high quantum efficiency and low operating voltage may be produced from this locked junction. The diodes may also be used for photovoltaic energy conversion. In a photovoltaic cell, the built-in potential helps separate electron-hole pairs and increases the open-circuit voltage.

Growing community of inventors

Temecula, CA, United States of America

Qibing Pei