Flexible Waterproof Piezoresistive Pressure Sensors with Wide Linear Working Range Based on Conductive Fabrics

Developing flexible sensors with high working performance holds intense interest for diverse applications in leveraging the Internet-of-things(IoT)infrastructures.For flexible piezoresistive sensors,traditionally most efforts are focused on tailoring the sensing materials to enhance the contact resistance variation for improving the sensitivity and working range,and it,however,remains challenging to simultaneously achieve flexible sensor with a linear working range over a high-pressure region(>100 kPa)and keep a reliable sensitivity.Herein,we devised a laserengraved silver-coated fabric as"soft"sensor electrode material to markedly advance the flexible sensor's linear working range to a level of 800 kPa with a high sensitivity of 6.4 kPa^-1 yet a fast response time of only 4 ms as well as long-time durability,which was rarely reported before.The integrated sensor successfully routed the wireless signal of pulse rate to the portable smartphone,further demonstrating its potential as a reliable electronic.Along with the rationally building the electrode instead of merely focusing on sensing materials capable of significantly improving the sensor's performance,we expect that this design concept and sensor system could potentially pave the way for developing more advanced wearable electronics in the future.

Highly Sensitive Pseudocapacitive Iontronic Pressure Sensor with Broad Sensing Range

Flexible pressure sensors are unprecedentedly studied on monitoring human physical activities and robotics.Simultaneously,improving the response sensitivity and sensing range of flexible pressure sensors is a great challenge,which hinders the devices’practical application.Targeting this obstacle,we developed a Ti_(3)C_(2)T_(x)-derived iontronic pressure sensor(TIPS)by taking the advantages of the high intercalation pseudocapacitance under high pressure and rationally designed structural configuration.TIPS achieved an ultrahigh sen-sitivity(S_(min)>200 kPa^(−1),S_(max)>45,000 kPa^(−1))in a broad sensing range of over 1.4 MPa and low limit of detection of 20 Pa as well as stable long-term working durability for 10,000 cycles.The practical application of TIPS in physical activity monitoring and flexible robot manifested its versatile potential.This study provides a demonstration for exploring pseudocapacitive materials for building flexible iontronic sensors with ultrahigh sensitivity and sensing range to advance the development of high-performance wearable electronics.

基于磁诱导微柱阵列可无线充电的超灵敏柔性传感器

为实现在宽感知范围内对微小压力变化的精确测量,提高柔性压力传感器的灵敏度和工作范围显得尤为迫切.然而,由于柔性传感器所使用的软基质材料的固有局限,实现超过100 kPa工作范围同时维持1000 kPa^(-1)以上的灵敏度仍然是一项挑战.本文报道了一种磁诱导的多孔弹性体(PDMS),分别以微柱阵列(MPA)作为传感材料和具有编织结构的导电镍作为电极.由于MPA的独特结构和电极的织构形态,所开发的传感器具有10,268 kPa^(-1)(0.6–170 kPa范围内)的超高灵敏度,高达500 kPa的工作范围,并具有长期耐用性.并实现了最小0.25 Pa的检测压力和3 ms的响应时间.此外,将柔性传感器、柔性超级电容器和感应线圈进行一体化集成,实现了对传感器的无线能量传输,并在低压至高压范围内对传感实际应用能力进行了测试.本项研究工作将具有微结构的高性能传感器与无线充电系统结合在一起,为开发下一代柔性电子产品提供了一种新颖的方法.

Stretchable and anti-impact iontronic pressure sensor with an ultrabroad linear range for biophysical monitoring and deep learning-aided knee rehabilitation

Monitoring biophysical signals such as body or organ movements and other physical phenomena is necessary for patient rehabilitation.However,stretchable flexible pressure sensors with high sensitivity and a broad range that can meet these requirements are still lacking.Herein,we successfully monitored various vital biophysical features and implemented in-sensor dynamic deep learning for knee rehabilitation using an ultrabroad linear range and highsensitivity stretchable iontronic pressure sensor(SIPS).We optimized the topological structure and material composition of the electrode to build a fully stretching on-skin sensor.The high sensitivity(12.43 kPa^(−1)),ultrabroad linear sensing range(1 MPa),high pressure resolution(6.4 Pa),long-term durability(no decay after 12000 cycles),and excellent stretchability(up to 20%)allow the sensor to maintain operating stability,even in emergency cases with a high sudden impact force(near 1 MPa)applied to the sensor.As a practical demonstration,the SIPS can positively track biophysical signals such as pulse waves,muscle movements,and plantar pressure.Importantly,with the help of a neuro-inspired fully convolutional network algorithm,the SIPS can accurately predict knee joint postures for better rehabilitation after orthopedic surgery.Our SIPS has potential as a promising candidate for wearable electronics and artificial intelligent medical engineering owing to its unique high signal-to-noise ratio and ultrabroad linear range.