Human tactioception provides extensive information about the environment upon contact or through interactions. Inspired by the physiological tactile functions, this proposal aims to develop a highly sensitive tactile array on flexible and transparent substrates, utilizing a novel capacitive sensing principle at a droplet electrolyte-electrode interface. Several unconventional microfabrication techniques will be established to devise this unique tactile sensors with all flexible components, including microfluidic matrix printing, wettability micropatterning, and interfacial nano-adhesion. Upon development, such an array of the microdroplet sensors would enable a highly transformative platform of artificial tactile sensing for a range of medical and robotic applications with high device sensitivity, high spatial resolution and high adaptability. Intellectual Merit: The novel bio-inspired tactile sensing matrix offers several advantages over existing sensing designs, including ultrahigh device sensitivity (the highest sensitivity of 0.12nF/kPa at its dimension), ultrafine spatial resolution (down to 0.5mm), dual pressure-temperature mapping capacity, fast response time (as quick as 1 milliseconds), ultralow profile with packaging (as thin as 100ìm), in addition to its skin-like construct made from all soft materials, e.g., polymers and liquids. Importantly, the interfacial capacitive sensor is highly immune to parasitic capacitance, in which the base capacitance is more than 100 times greater than that of the conventional counterpart. Moreover, the simple device architecture permits mass-production at low cost yet high reliability. Overall, the proposed bio-inspired iontronic sensors, once established, could offer a highly transformative solution to various fundamental and translational fields of neural processing, robotics, medical prosthetics, computer/video gaming, and surgical instruments, where both high flexibility and sensitive responses are demanded. Broader Impacts: Exciting discoveries from the proposed research will be fully integrated with the educational efforts. The PI has been actively promoting education of cutting-edge micro-nanotechnology at all levels. He is actively engaged in disseminating the out-of-cleanroom microfabrication concept by converting consumer electronics into desktop microfabrication tools to the general public through online open-access channels. Through the K-12 educational outreach, the PI will lead an outreach initiative of Introducing Tactile Sensing into K-12 Classroom by turning the research discoveries on the artificial tactile sensing to a plug-and-play demonstration kit for local high-school students. Moreover, education opportunities will be directly provided to underrepresented undergraduate and high-school students on bio-inspired sensing concepts through a NSF-sponsored summer internship program.
