Laser-scribed graphene for sensors:preparation,modification,applications,and future prospects

Sensors are widely used to acquire biological and environmental information for medical diagnosis,and health and environmental monitoring.Graphene is a promising new sensor material that has been widely used in sensor fabrication in recent years.Compared with many other existing graphene preparation methods,laser-scribed graphene(LSG)is simple,low-cost,environmentally friendly,and has good conductivity and high thermal stability,making it widely used in the sensor field.This paper summarizes existing LSG methods for sensor fabrication.Primary LSG preparation methods and their variants are introduced first,followed by a summary of LSG modification methods designed explicitly for sensor fabrication.Subsequently,the applications of LSG in stress,bio,gas,temperature,and humidity sensors are summarized with a particular focus on multifunctional integrated sensors.Finally,the current challenges and prospects of LSG-based sensors are discussed.

Micromesh reinforced strain sensor with high stretchability and stability for full-range and periodic human motions monitoring

The development of strain sensors with high stretchability and stability is an inevitable requirement for achieving full-range and long-term use of wearable electronic devices.Herein,a resistive micromesh reinforced strain sensor(MRSS)with high stretchability and stability is prepared,consisting of a laser-scribed graphene(LSG)layer and two styrene-block-poly(ethylene-ran-butylene)-block-poly-styrene micromesh layers embedded in Ecoflex.The micromesh reinforced structure endows the MRSS with combined characteris-tics of a high stretchability(120%),excellent stability(with a repetition error of 0.8%after 11000 cycles),and outstanding sensitivity(gauge factor up to 2692 beyond 100%).Impressively,the MRSS can still be used continauously within the working range without damage,even if stretched to 300%.Furthermore,compared with different structure sensors,the mechanism of the MRSS with high stretchability and stability is elucidated.What's more,a multilayer finite element model,based on the layered structure of the LSG and the morphology of the cracks,is proposed to investigate the strain sensing behavior and failure mechanism of the MRSS.Finally,due to the outstanding performance,the MRSS not only performes well in monitoring full-range human motions,but also achieves intelligent recognitions of various respiratory activities and ges-tures assisted by neural network algorithms(the accuracy up to 94.29%and 100%,respectively).This work provides a new approach for designing high-performance resistive strain sensors and shows great potential in full-range and long-term intelligent health management and human-machine interac-tions applications.