A flexible sensing system capable of sensations imitation and motion monitoring with reliable encapsulation

•An encapsulation method for flexible electronics with excellent reliability is proposed.•A skin like system capable of imitating different sensations of the human skin is proposed.•A robot hand equipped with the flexible system can be used for judging the stiffness and the shape of the grasped subject. In this work, a flexible multiple sensor system is demonstrated for robotic and prosthetic applications. The system consists of two strain sensors, a microheater, a temperature sensor and a pressure sensor for imitating different sensations of human skin. The strain sensors are designed for monitoring the movement and bending angle of the fingers; while the temperature and pressure sensors are used to collect the information of temperature, grabbing force and stiffness of the objects being grabbed, respectively. Combination of the temperature sensor and microheater mimics the temperature sensation of human skin, allowing measuring temperature and apparent temperature of the objects grasped. Liquid metal with reliable polymer encapsulation is innovatively used to interface the sensor system with peripheral circuits. This allows reliable signal transmission and processing for the flexible sensor system for strains up to 40%. This multiple sensor system is capable of precisely monitoring movement of fingers, providing different sensations and judging some characteristics of objects for a robot hand.