A Wearable Flexible Tactile Sensor with Textile Microstructure for Wirelessly Recognizing Human Activity

Abstract

AbstractFlexible tactile sensors have attracted special attention in the detection of human posture and activity. However, achieving multiple stimulus responses is particularly challenging in terms of structural design and has not been fully addressed. Herein, a novel structural design inspired by combining the characteristics of a strain sensor and e‐textile into a hybrid interface to obtain stretchable multiple stimulus‐responsive tactile sensors (stretching stimulus, pressing stimulus, and bending stimulus) is proposed. The sensitive layer of the sensor is designed as a textile microstructure. The sensor, which has a stable performance with excellent ohm property and durability (>2 years), possesses an extraordinary gauge factor (≈200) and a fast response time (≈2.48 ms) under tensile strain, a high sensitivity (≈2.35 kPa−1) in a low‐pressure range (≈9 kPa) under pressure. It has excellent performance for Human Activity Recognition by being attached to human skin. In addition, a Bluetooth device that tracks muscle activity in real‐time and transmits the output signals to a smartphone application is utilized. These results imply the utility of this sensor for a diverse application of robotic e‐skins or e‐muscles.