Recent progress of flexible and wearable strain sensors for human-motion monitoring

Abstract

With the rapid development of human artificial intelligence and the inevitably expanding markets, the past two decades have witnessed an urgent demand for the flexible and wearable devices, especially the flexible strain sensors. Flexible strain sensors, incorporated the merits of stretchability, high sensitivity and skin-mountable, are emerging as an extremely charming domain in virtue of their promising applications in artificial intelligent realms, human-machine systems and health-care devices. In this review, we concentrate on the transduction mechanisms, building blocks of flexible physical sensors, subsequently property optimization in terms of device structures and sensing materials in the direction of practical applications. Perspectives on the existing challenges are also highlighted in the end.

Wearable and Stretchable Strain Sensors: Materials, Sensing Mechanisms, and Applications

“…Finally, favorable applications of wearable strain sensors and current challenges are highlighted, and an outlook is presented. Unlike recent review papers focusing on a specific type of strain sensors, [11,[21][22][23][24][25][26] this Review thoroughly covers all major types of wearable strain sensors, explicitly categorizes strain sensing parameters, and gives a detailed sensing comparison among recently reported wearable strain sensors. Compared with our previous Feature article, [1] this article further reviews optical and textile-based stretchable strain sensors and comprehensively discusses potential applications of wearable and stretchable strain sensors.…”

Carbon fibre based flexible piezoresistive composites to empower inherent sensing capabilities for soft actuators

“…In terms of potential sensing mechanisms, a detailed overview of flexible and tactile sensing has been provided in key reviews [21][22][23][24][25][26] where a variety of sensing mechanisms have been used such as piezoresistance (a change in resistance with stress), piezocapacitive (a change in capacitance with stress), and piezoelectric (voltage or charge generation with stress). With regard to piezoresistive sensing, these materials are often based on conductive materials embedded in an insulating matrix which leads to a change in electrical conductivity with stress or strain.…”

A Path Beyond Metal and Silicon:Polymer/Nanomaterial Composites for Stretchable Strain Sensors

“…The fabrication methods of stretchable composite strain sensors were categorized into liquid‐phase mixing,[22c,64b,73] chemical vapor deposition,[3c,70,71,74] printing, coating,[4d,76] filtration,[3b,77] and transferring . Although fabrication details and sensing mechanisms are available in recent reviews, we briefly introduce the fabrication below. The liquid‐phase mixing simply blends conductive nanomaterials into elastomers in liquid state.…”