Full‐Range On‐Body Strain Sensor of Laser‐Induced Graphene Embedded in Thermoplastic Elastomer via Hot Pressing Transfer for Monitoring of the Physiological Signals

Abstract

Acquiring physical and mechanical strain information of the human body with wearable strain sensors can provide essential data from personal healthcare to human‐machine interfaces and others. Recent research reveals that CO2 laser scribing can convert polyimide films into porous graphene sponges under ambient atmospheres. However, the electrically conductive laser‐induced graphene (LIG) film mismatches with the tough and rigid plastic substrates when it is employed as stretchable strain sensors. In this work, by leveraging the advantageous properties of atoms‐level configured defects within crystalline LIG and heat transfer printing techniques, a flexible LIG‐SEBS (styrene‐ethylene‐butylene‐styrene) strain sensor is made. It is able to achieve exceptional electromechanical properties including a remarkable sensitivity in terms of gauge factor (413–3118), minimal hysteresis, and a broad strain range (>100% strain). Meanwhile, the SEBS‐LIG strain sensor has a stable and fast dynamic response and good repeatability. Additionally, the sensor can be integrated with a wireless communication module for remote monitoring of physiological signals in a real‐time manner with a smartphone App.

Laser-Scribed Graphene for Human Health Monitoring: From Biophysical Sensing to Biochemical Sensing

“…Although the composite materials provide the superior mechanical stability required for strain sensing, the elastomer covering part of the LSG surface inevitably impairs its performance as a sensing electrode. Recently, Liu et al observed plenty of carbon vacancies in the crystalline lattice of LSG by examining the microstructure of atom-layer thin LSG flakes [ 42 ]. These atom-level configured defects may induce fractures or delamination within LSG sponges.…”