High-performance fingerprint bionic Ecoflex@AgNW/graphite/Pt hybrid strain sensor

Wearable electronics have promising applications in human-machine interfaces due to their excellent flexibility,stretchability and human friendliness,and one of the key points of wearable electronics is to develop strain sensors with high sensitivity and working range.Herein,a high-performance Eco-flex@AgNW/graphite/Pt hybrid strain sensor was fabricated by suction filtrating,transferring and surface sputtering sequentially.The suction filtrating of AgNW and graphite dispersions on a wrinkle-shape Nylon filter,transferring of AgNW/graphite layer onto Ecoflex and further surface sputtering by Pt allow the construction of fingerprint bionic Ecoflex@AgNW/graphite/Pt hybrid strain sensor.The resul-tant fingerprint bionic hybrid strain sensor possesses high sensitivity of 2064.1 at the strain of 140%e155%,a wide working range of 0e155%,a short response time(111 ms and 189 ms for tensile and releasing process)and excellent cyclic stability over 5000 cycles.This study provides a universal tech-nique for the preparation of strain sensors with promising applications in the field of next-generation intelligent wearable electronics.

Stress-deconcentrated ultrasensitive strain sensor with hydrogen-bonding-tuned fracture resilience for robust biomechanical monitoring

Recently,rapid advances in flexible strain sensors have broadened their application scenario in monitoring of various mechanophysiological signals.Among various strain sensors,the crack-based strain sensors have drawn increasing attention in monitoring subtle mechanical deformation due to their high sensitivity.However,early generation and rapid propagation of cracks in the conductive sensing layer result in a narrow working range,limiting their application in monitoring large biomechanical signals.Herein,we developed a stress-deconcentrated ultrasensitive strain(SDUS)sensor with ultrahigh sensitivity(gauge factor up to2.3×10^(6))and a wide working range(0%-50%)via incorporating notch-insensitive elastic substrate and microcrack-tunable conductive layer.Furthermore,the highly elastic amine-based polymer-modified polydimethylsiloxane substrate without obvious hysteresis endows our SDUS sensor with a rapid response time(2.33 ms)to external stimuli.The accurate detection of the radial pulse,joint motion,and vocal cord vibration proves the capability of SDUS sensor for healthcare monitoring and human-machine communications.

Modeling and experiments of a nano-positioning and high frequency scanning piezoelectric platform based on function module actuator

A piezoelectric platform using function module actuator is presented to achieve nano-positioning and high frequency scanning in large working range. A function module actuator is designed to produce a pair of orthogonal bending deformations and a longitudinal deformation through partition exciting. The bending deformations are used to actuate the planar motion,while the longitudinal deformation is utilized to dynamically adjust the driving force and broaden the scanning frequency. The dynamic model of the platform system is developed. The open-loop performances of a prototype are first tested: a scan frequency of 308 Hz in a scanning range of 3.368 μm×3.396 μm is measured in direct actuation mode,and the displacement resolution is measured to be 16 nm;maximum speed is measured to be 3.38 mm s^-1 in the inertial actuation mode. Furthermore,the closedloop experiments are carried out and a switching strategy is proposed to obtain the switching of the inertial and direct actuation modes automatically;the platform achieves the scanning with frequency of 300 Hz at the set position.