Wisconsin Alumni Research Foundation

United States of America, As Represented by the Secretary of Agriculture

Xudong Wang

Jun Li

Fei Wang

Zhenqiang Ma

Jung-Hun Seo

Zhiyong Cai

Weibo Cai

Chunhua Yao

Yanchao Mao

Yingjin Wei

Jian Shi

Yutao Dong

Alexander V Kvit

Qiang Pang

Ping Zhao

Hao Wei

Fan Yang

Alberto Hernandez

Yan Shao

Yin Long

Guang Yao

Yanhao Yu

Lei Kang

Zhaodong Li

An encapsulation for an implantable medical device is provided defined by a blend of high molecular weight polyisobutylene and low molecular weight polyisobutylene solution to provide desirable stretchability and elastic properties without sacrificing water resistance properties of the encapsulation. The encapsulation material is flexible thus allowing the medical device to possess tissue matching flexibility and retain long-term normal function free from liquid infiltration.

Stretchable encapsulation material with high dynamic water resistivity and tissue-matching elasticity

A flexible piezoelectric thin film, and method of manufacture, has a polyvinyl alcohol (PVA)-glycine-PVA sandwich heterostructure. The thin film is manufactured by evaporating the solvent from a glycine-PVA mixture solution. The film automatically assembles into the PVA-glycine-PVA sandwich heterostructure as it is salted out. Strong hydrogen bonding between the oxygen atoms in glycine and hydroxyl groups on PVA chains are responsible for the nucleation and growth of the piezoelectric γ-glycine and alignment of the domain orientation.

Wafer-scale piezoelectric bio-organic thin films

An in-situ poled ferroelectric prints with true 3D geometry is provided with an intercalated electrode design where soft polymer matrixes are selected for the ferroelectric layers, and rigid polymer matrixes are selected for the electrode layers, thus mimicking nacre architecture with a ceramic-like piezoelectric property and bone-like fracture toughness. Lithium-doped potassium sodium niobite (Li—KNN) microparticles may be used to produce ferroelectric properties and to create strong interfacial bonding with the interfacing electrode layers. Polylactic acid (PLA) in the electrode layers may be used to facilitate strong interfacial bonding with the Li—KNN microparticles.

3D-printed ferroelectric metamaterial with giant piezoelectricity and biomimetic mechanical toughness

An energy harvesting system for use with the human body may use an eccentrically mounted weight winding a mainspring that drives a mechanical clock mechanism. The mechanical clock mechanism in turn may produce pulses of electricity, for example, through periodic flexing of a piezoelectric or triboelectric material during the regular motion of the mechanical timing mechanism. By remaining in a mechanical rather than electrical domain, improved simplicity and efficiency may be obtained in the generation of regularly spaced uniform pulses.

Electrical pulse generator harvesting body movement energy

A piezoelectric artificial artery can be 3D printed to provide the real-time precise sensing of blood pressure and vessel motion patterns enabling early detection of partial occlusions. An electric-field assisted 3D printing method allows for rapid printing and simultaneously poled complex ferroelectric structures with high fidelity and good piezoelectric performance. The print material consists of ferroelectric potassium sodium niobate (KNN) particles embedded within a ferroelectric polyvinylidene fluoride (PVDF) polymer matrix.

3D printed and in-situ poled flexible piezoelectric pressure sensor

A transient or biodegradable battery is provided having a filament structure that limits the speed of reaction allowing for a longer duration of battery power with a controlled current limit. In one embodiment, the filament may be constructed of zinc microparticles or nanoparticles having a thin outer insulation whereby a chemical reaction at the center core results in the progressive disintegration of the insulation revealing more core material. In one embodiment, microparticles or nanoparticles are coated with outer layers of chitosan and AlOnanofilms, respectively, with designable discharge current and battery lifespan by controlling the exposed cross-sectional area of the zinc microparticle center core and the length of the filament, respectively. This novel structure of biodegradable battery provides improved control of battery life and power output, providing a promising solution to power transient medical implants.

Biodegradable transient battery built on core-double-shell zinc microparticle networks

A wearable medical bandage is provided having an energy harvesting generator that harvests mechanical energy from the user's natural body and muscle motions to produce electrical energy. The electrical energy induces an electric potential across the wound opening producing accelerated skin wound recovery under the voltage fluctuations produced by the power generator.

Electric bandage for accelerated wound recovery

The invention provides an implantable vagal nerve stimulator having a 'passive' generating power source that harvests the stomach's movements to transform kinetic energy to electrical charge without the need for a battery. In this regard, the invention is self-powering and is automatically timed to stomach peristalsis. While sporadic stimulation to the vagal nerve would seem too infrequent to cause weight loss effects, electrical stimulation delivered at the optimal time (e.g., during food consumption) has been found to optimize the effects of vagal nerve stimulation, giving the user's brain a 'full stomach' signal before the user over-consumes food.

Self-powered, auto-responsive implanted vagal nerve stimulator for weight control

An aqueous rechargeable zinc ion battery is provided, the battery comprising a cathode comprising a VO.HO-graphene composite, the composite comprising a plurality of VO.HO nanostructures in contact with graphene, an anode in electrical communication with the cathode, the anode comprising zinc, and an aqueous electrolyte between the cathode and the anode, the aqueous electrolyte comprising zinc ions and an ether of a type and at an amount selected to maximize a capacity retention value of the battery.

Composite electrode for aqueous rechargeable zinc ion batteries

Triboelectric nanogenerators that operate in a vertical contact separation mode and methods for fabricating the triboelectric generators are provided. Also provided are methods for using the triboelectric nanogenerators to harvest mechanical energy and convert it into electric energy. In the TENGs, one or both of the triboelectrically active layers comprises a cellulose that has been chemically treated to alter its electron affinity.

Triboelectric nanogenerators based on chemically treated cellulose

Photocatalytic structures having a capillary-force based electrolyte delivery system are provided. Also provided are photoelectrochemical and photocatalytic cells incorporating the structures and methods for using the cells to generate hydrogen and/or oxygen from water. The photocatalytic structures use an electrolyte-transporting strip comprising a porous network of cellulose nanofibers to transport electrolyte from a body of the electrolyte to a porous photoelectrode or a porous photocatalytic substrate via capillary force.

Capillary photoelectrode structures for photoelectrochemical and photocatalytic cells

Methods of making electrically conductive, doped zinc oxide nanowires and nanowire films are provided. The methods comprises the steps of forming an aqueous solution comprising a dopant-containing precursor salt, a zinc-containing precursor salt and a pH buffering agent and heating the aqueous solution to a temperature below its boiling point in the presence of seed crystals, whereby doped zinc oxide nanowires are grown in situ from the seed crystals in the aqueous solution.

Solution-based synthesis of doped ZnO nanostructures

Piezoelectric materials based on nanoporous polymer foams are provided. Also provided are nanogenerators incorporating the piezoelectric materials, piezoelectric energy harvesters incorporating the nanogenerators and methods of making and using the same. The piezoelectric materials comprise a unitary nanoporous matrix composed of a piezoelectrically active organic polymer, in which the pores are interconnected and have nanoscale diameters.

Nanoporous piezoelectric polymer films for mechanical energy harvesting

The present invention provides continuous, free-standing metal oxide films and methods for making said films. The methods are able to produce large-area, flexible, thin films having one or more continuous, single-crystalline metal oxide domains. The methods include the steps of forming a surfactant monolayer at the surface of an aqueous solution, wherein the headgroups of the surfactant molecules provide a metal oxide film growth template. When metal ions in the aqueous solution are exposed to the metal oxide film growth template in the presence of hydroxide ions under suitable conditions, a continuous, free-standing metal oxide film can be grown from the film growth template downward into the aqueous solution.

Methods for making large-area, free-standing metal oxide films

Methods for growing a three-dimensional nanorod network in three-dimensional growth spaces, including highly confined spaces, are provided. The methods are derived from atomic layer deposition (ALD) processes, but use higher temperatures and extended pulsing and/or purging times. Through these methods, networks of nanorods can be grown uniformly along the entire inner surfaces of confined growth spaces.

Growing community of inventors

Middleton, WI, United States of America

Xudong Wang