Stretchable organic electrochemical transistors via threedimensional porous elastic semiconducting films for artificial synaptic applications

Neuromorphic computing targets realizing biomimetic or intelligence systems capable of processing abundant tasks in parallel analogously to our brain,and organic electrochemical transistors(OECTs)that rely on the mixed ionic-electronic synergistic couple possess significant similarity to biological systems for implementing synaptic functions.However,the lack of reliable stretchability for synaptic OECTs,where mechanical deformation occurs,leads to consequent degradation of electrical performance.Herein,we demonstrate stretchable synaptic OECTs by adopting a three-dimensional poly(3-hexylthiophene)(P3HT)/styrene-ethylene-butylene-styrene(SEBS)blend porous elastic film for neuromorphic computing.Such architecture shows the full capability to emulate biological synaptic behaviors.Adjusting the accumulated layer numbers of porous film enables tunable OECT output and hysteresis,resulting in transition in plasticity.Especially,with a trilayer porous film,large-scale conductance and hysteresis are endorsed for efficient mimicking of memory-dependent synapse behavior.Benefitted from the interconnected three-dimensional porous structures,corresponding stretchable synaptic OECTs exhibit excellent mechanical robustness when stretched at a 30%strain,and maintain reliable electrical characteristics after 500 stretching cycles.Furthermore,near-ideal weight updates with near-zero nonlinearities,symmetricity in long-term potentiation(LTP)and depression,and applications for image simulation are validated.This work paves a universal design strategy toward highperformance stretchable neuromorphic computing architecture and could be extended to other flexible/stretchable electronics.

Soft-switching SiC power electronic conversion for distributed energy resources and storage applications

Power electronic conversion plays an important role in flexible AC or DC transmission and distribution systems,integration of renewable energy resources,and energy storage systems to enhance efficiency,controllability,stability,and reliability of the grid.The efficiency and reliability of power electronic conversion are critical to power system applications.One way to enhance the efficiency and reliability of power electronic conversion is soft-switching technology.This paper introduces a generic zero-voltage-switching(ZVS)technique based on silicon carbide(Si C)power device.Using the proposed ZVS technique,all semiconductor switching devices in a power converter can realize ZVS operations.Next,the applications of the ZVS technique in different power electronic conversion systems such as photovoltaic inverters,wind power systems,energy storage systems and flexible AC transmission system devices are discussed.Finally,as an example,the operation performance and efficiency improvement of a Si C metal-oxide-semiconductor field-effect transistor(MOSFET)ZVS back-to-back converter are discussed.