Laser Induced Graphene/Silicon Carbide: Core–Shell Structure, Multifield Coupling Effects, and Pressure Sensor Applications

Abstract

AbstractLatest advances have witnessed the laser scribing of various active materials from synthetic polymers to natural sources without masks, post‐treatment, or toxic substances. However, laser induced graphene (LIG) on renewable precursors usually requires flame‐retardant pretreatment and multistep pulsed or defocused irradiation. Laser scribing of silicon carbide (SiC) from polydimethylsiloxane (PDMS) is limited by its high transparency over a broad wavelength range. Here, a structural design strategy is adopted to solve these two dilemmas at the same time, that is, laser scribing of carbonized cloth/PDMS to prepare LIG/SiC composites. Natural cotton cloth is precarbonized and inserted in PDMS substrate to facilitate heat absorption for the in situ formation of SiC, while the soft PDMS attached to the carbonized cloth absorbs heat and isolates oxygen, enabling the conversion of amorphous carbon to LIG. Under these multifield coupling effects, a core–shell LIG/SiC electrode is formed on the carbonized cloth with tunable mass ratio, morphology, and graphene defects. Experimentally, the LIG/SiC pressure sensor exhibits a good sensitivity of 1.91 kPa−1 in the super‐wide sensing range of 0–226.7 kPa. By demonstrating different scenarios such as real‐time monitoring of large body movements, tiny pulses and heartbeats, the flexible pressure sensors hold great promise in wearable electronics.