Enhanced Graphene Sensors via Multi-Lasing Fabrication

Abstract

Resistive strain and bending sensors offer a versatile platform for sensing various physical parameters with relatively little effort and budget. The lightweight, robust and compact sensors are extensively used in manifold low-power applications. Recently, scribed and flexible laserinduced graphene sensors have shown potent capabilities for a variety of measurements, including flow, deflection, and force. Achieving a high sensitivity to various stimuli remains a challenge due to limited change in relative resistance. In this paper, we report a multifunctional LIG sensor with widely tunable properties and significantly enhanced electromechanical performance. A method of repeated laser writing is used to increase the porosity, the uniform carbonization degree and, most importantly, the sensitivity of the LIG sensors. A gauge factor of 91.2 is achieved after three-times laser writing at low power, which is an increase of 750% to one-time laser writing and 720% higher than the ones previously reported for LIG strain sensors. The increase is attributed to a more porous surface morphology that provides more overlapping area and displacement of the graphene layers. A homogeneous bidirectional response was obtained by scribing the electrodes on both faces of the substrate. Parylene C-coating is used to protect the LIG sensors from environmental effects. Coated sensors were packaged to a PCB assembly for easy integration into various applications. An example is a LIG bending sensor customized for velocity profile monitoring of Unmanned Aerial Vehicles in the outdoor environment.

Bioderived Laser-Induced Graphene for Sensors and Supercapacitors

“…LIG-based PS is able to measure a variety of parameters, including strain, pressure, bending, humidity, and temperature. They are of high relevance in several application fields, such as healthcare for humans and animals (e.g., heart rate, pulse monitoring, plantar pressure), environmental monitoring (e.g., temperature detection, gas sensing, pressure and humidity sensing), and robotics (e.g., tactile sensing, gesture-based control, sound detecting, proximity, and positioning) . The possibility of using bioderived LIG precursors is particularly interesting for PS because of the possible applications for transient electronics, such as soil moisture monitoring and bioresorbable pressure sensing .…”

“…They are of high relevance in several application fields, such as healthcare for humans and animals (e.g., heart rate, pulse monitoring, plantar pressure), environmental monitoring (e.g., temperature detection, gas sensing, pressure and humidity sensing), and robotics (e.g., tactile sensing, gesture-based control, sound detecting, proximity, and positioning). 170 The possibility of using bioderived LIG precursors is particularly interesting for PS because of the possible applications for transient electronics, such as soil moisture monitoring 171 and bioresorbable pressure sensing. 172 This section takes a look at the different types of PS from bioderived LIG and compares them to the performance of PI-derived LIG sensors (Table 8).…”