Journal of Bionic Engineering (2025) 22:713–726 https://doi.org/10.1007/s42235-024-00644-x

Laser-induced and Conformal liquid-silicone Casting of oxalis-inspired  graphene-based Piezoresistive Pressure Sensors 

Wentao Wang1  · Zeping Deng1  · Ziqiang Chen1  · Linfeng Yuan1  · Junyan Xiang1  · Longzhou Dai1  · Kun Tang1

1 School of Automotive and Mechanical Engineering,  Changsha University of Science and Technology,  Changsha 410114, China

Abstract 

Laser-Induced Graphene (LIG) is regarded as a promising sensor carrier due to its inherent three-dimensional porous  structure. However, as two mutually exclusive properties of the pressure sensor, sensitivity and working range are difficult  to be further improved by the single porous structure. Inspired by the unique geometry of Oxalis corniculata L. leaves,  we here propose a novel method consist of laser pre-etching and inducing steps to fabricate LIG-based electrodes with a  two-stage architecture featuring microjigsaw and microporous structures. The following injection of liquid-silicone significantly improves the friction resistance and bending reliability of LIG materials. The interface contact between external  microjigsaw structures induces substantial resistance changes, and the internal microporous structure exhibits reversibility  during dynamic deformation. Consequently, the jigsaw-like pressure sensor achieves a balanced performance with sensitivities of 3.64, 1.20 and 0.03 kPa?1  in pressure range of 0?20, 20?40 and 40?150 kPa, respectively. The bionic LIG-based pressure sensor serves as the core component and further integrated with an all-in-one wireless transmission system  capable of monitoring various health parameters such as subtle pulse rates, heartbeat rhythms, sounds, etc., indicating  broad prospects in future wearable electronics. 

Keywords Oxalis corniculata L. leaves · Bionic · Laser-induced graphene · Flexible pressure sensor · Mircojigsaw