PEGgel-Based Multimodal Soft Sensors Capable of Decoupling Thermal and Mechanical Stimuli

Inspired by human skin, soft sensors that are capable of sensing various external signals have been an active area of research. However, the vast majority of the developed soft sensors still lag far behind human skin in terms of multimodal sensing capability. Herein, this work reports on a multimodal soft sensor that can decouple thermal and mechanical signals. The sensor is made of poly(ethylene glycol) gel (PEGgel) containing ionic liquid, which is stretchable and transparent and shows decent strain and temperature sensing performances. Importantly, analysis of the ion relaxation dynamics shows that the charge relaxation time and capacitance change of the sensor are independently sensitive to the variations of temperature and mechanical deformation, respectively. By measuring the charge relaxation time and capacitance, the thermal and mechanical signals detected by the PEGgel sensor can be nicely decoupled without signal interference. Such a multimodal soft sensor may serve as a starting point for the development of lifelike soft sensors for high-tech applications in a variety of fields such as soft robotics, the internet of things, and human-machine interaction. A soft sensor consists of a stretchable and conductive PEGgel is present with excellent strain and temperature sensing abilities. On the basis of the analysis of the ion relaxation dynamics, the soft sensor is able to sense temperature and mechanical deformation independently and shows great potential in the field of soft robotics, the internet of things, and human-computer interaction. image