A wearable and fully-textile capacitive sensor based on flat-knitted spacing fabric for human motions detection

The rapid development of flexible wearable intelligent devices has continuously promoted people to put forward higher standards for wearability, portability, lightweight and dimensional flexibility of emerging device components. In this work, a flexible capacitive sensor based on elastic spacer fabric was knitted by flat knitting. The spacer fabrics showed good compression recovery and mechanical stability under different strains and frequencies, conferring the capacitive sensor with excellent capacitance characteristics, such as high elasticity, excellent capacitance characteristics under different compression frequencies and strains, fast response time less than 150 ms under compression strain of 30%, as well as high stability of the sensor for compressing over 2000 cycles at 50% strain. Benefited from the excellent sensing performances and stable structure, the sensor can be used for various pressure detections such as finger pressing, plantar pressure, fist force, etc., indicating its promising application in flexible and wearable devices.