|
Soft and Stretchable Dielectric with Reliable Electrical Performance
This invention demonstrates a stretchable form of dielectric that maintains its electrical performance even in highly conductive environments for an extended period of time. This is achieved by embedding a layer of liquid metal in the soft and stretchable dielectric materials to effectively stop the diffusions of conductive matters diffusing/penetrating through the polymeric matrix network while maintaining the stretchability.
|
|
|
Flow Sensor Based on Coulometric Interrogation of a Graphene Microelectrode
[%SearchResultsTechnologyDescription%]
|
|
|
CAPACITIVE ARTIFICIAL NEURAL NETWORKS
|
|
|
ARTIFICIAL NEURONS USING DIFFUSIVE MEMRISTOR
[%SearchResultsTechnologyDescription%]
|
|
Thermoelectric Facades
Buildings consume 40% of energy in the United States, and influence greenhouse gas emissions. Given the high energy usage and inefficiencies found in conventional HVAC systems, new heating and cooling sources are needed to reduce buildings’ carbon footprint. Moreover, integration of different building systems, particularly building envelope and HVAC, are essential for high-performance buildings. Here, the inventors have conceived and demonstrated the thermoelectric facade, a novel facade system that integrates active and conventional thermoelectric (TE) modules for cooling, heating and energy generation. TE modules generate heat or cooling when electricity is applied, exploiting the Peltier effect, and produce a voltage when exposed to a temperature gradient, utilizing the Seebeck effect. Coupled with heat sinks, conductive materials and an electronic controller, the TE modules are employed in the facade system to heat or cool interior spaces of buildings, providing highly efficient and localized thermal management without requiring ducting, piping, or other large installations commonly associated with forced-air systems. In addition, thermoelectric facades can take advantage of temperature differences between interior and exterior to generate electricity at those times when active heating or cooling is not in use. This novel, intelligent facade system can be integrated into various facade types, regardless of the building function. Its modularity allows for easy installation into façade assemblies of the existing buildings, increasing the overall energy performance of the building. Additionally, they can be used in the design and construction of new buildings with various types of building envelope, including curtain walls, rainscreen facades with aluminum cladding, opaque facades with window and vertical shading, and/or opaque facades with window and horizontal shading.
|
High-Yield High-Quality Graphene by exfoliation of graphite
Graphene sheets are prized for their unusual but exciting properties, including extremely high mechanical strength and ability to efficiently conduct heat and electricity. These properties open up a myriad of applications in medicine, electronics, energy, and sensors. However, the production of graphene, which is derived from the exfoliation of graphite, is currently challenged by low efficiency and long exfoliation times. This invention uniquely combines two techniques, flow and sonication, to overcome these challenges. A graphite suspension is first subjected to a flow process, where it is mixed with zirconium oxide pebbles. Collisions between the graphite and the pebbles modify the graphite’s surface, making it easier for the solvent molecules to “wedge” in between layers during subsequent sonication, significantly increasing graphene exfoliation time-efficiency.
|
Hierarchically Ordered Nanoscale Electric Field Concentrators for Embedded Thin Film Devices
Resistance switching devices, also known as memristive devices, represent the next generation in computing. With a typical metal-oxide-metal structure, memristors change resistance under different external biases and retain this new resistance even when power is turned off. This allows memristors to store data without needing constant power like in traditional computer memory. Memristors have other desirable properties such as low power consumption, fast switching speed, and multistate logic potential. These properties open up next generation computing applications in non-volatile memory, reconfigurable switches, bio-inspired neuromorphic computing, and radiofrequency switches. However, before these applications are enabled, significant technical challenges in memristors must be overcome. These include cycle-to-cycle instabilities in operating voltage and resistance states, which cause memory retention and device endurance issues. Professor Stephen Nonnenmann and his laboratory address these instability issues by embedding highly ordered metal nanoislands in the memristor’s oxide switching layer. Through a unique template-directed nanoisland embedding procedure, the nanoisland diameter, spacing, and area density can be precisely controlled. The Nonnenmann lab found that through precise control of these variables, the growth of conductive filaments formed through the memristor’s oxide layer, which enable its unique properties, can be more precisely controlled, leading to a nearly 100% improvement in uniformity performance in one device case.
|
Neuromorphic Computing Memristive Device
Resistance switching devices, also known as memristive devices, represent the next generation in computing. With a typical metal/insulator/metal structure, memristors change resistance based on past current flow and retain this new resistance even when turned off. This allows memristors to store data without needing constant power like in traditional computer memory. Memristors have other desirable properties such as low power consumption, fast switching speed, and great cycling ability. These properties open up next generation computing applications in non-volatile memory, reconfigurable switches, bio-inspired neuromorphic computing, and radiofrequency switches. Here, Dr. Qiangfei Xia and Dr. Joshua Yang have invented a Ta/HfO2/Pt memristive device that can be used for multilevel memory and for neuromorphic computing. The device exhibits bipolar resistive switching with low programming voltage (~1.5 V), high endurance (100 billion cycles), and long data retention time (37,000 years at 85 C). The device can be programmed to multiple resistance states with long retention time for each individual state. Finally, spike dependent plasticity (STDP) is also demonstrated for this device. The device also has the advantage of being able to be fabricated using traditional CMOS materials and techniques.
|
Low Cross-Polarization Decade-Bandwidth Ultra-Wideband Antenna Element + Array
Electronically scanned arrays with ultra-wideband (ESA-UWBs) performance are desirable for applications such as multi-functional systems, high-throughput or low-power communications, high-resolution and clutter resilient radar/sensing, and electromagnetic warfare systems. For these applications, Vivaldi arrays are popular for their excellent impedance performance, but do suffer from unintended polarization, which leads to loss of service or reduction of throughput. To correct for these problems, one can add additional feeding circuitry; however, that will add to complexity and cost and reduce bandwidth capability.This invention improves upon prior art Vivaldi designs, creating an antenna that has: (1) large instantaneous bandwidths; (2) excellent impedance matching; (3) good polarization isolation. Dr. Vouvakis' antenna is also easier to manufacture because the body is made up of smaller disconnected components that are easier to solder and notch than a single long flair Vivaldi of the prior art. Finally, because the design is based on Vivaldi, this antenna invention will be backwards compatible with legacy wideband phased array platforms.
|
|
Ultra-Compact Low-Cost Terahertz Integrated Circuits
Terahertz imaging is becoming an increasingly important non-destructive evaluation method, with biomedical, security, aerospace, and materials characterization applications. However, unlike microwave-based systems, terahertz devices cannot be cheaply mass produced as integrated circuits, limiting their potential. In this invention, a compact, low-cost terahertz source has been developed that may be easily integrated into several common high-frequency integrated circuit designs, such as microstrip and coplanar waveguide. In operation, the source, palladium or platinum strips or nanowires, emits terahertz radiation upon Joule heating caused by applying a low frequency voltage. The source is electromagnetically coupled to antennas via integrated circuit techniques, and the terahertz radiation emitting from the antennas is collimated by a silicon lens. The required power to generate the radiation is extremely low, on the order of 15 nW. The UMass Terahertz Laboratory has successfully demonstrated the technology in a number of applications, including characterizing RNA flowing through a nanofluidic channel and imaging the crystalline polymer PHB.
|
