Flexible Hall sensor made of laser-scribed graphene

By Altynay Kaidarova,Wenhao Liu,Abdullah Almansouri,Carlos.M Duarte,Nathan R Geraldi,Liam Swanepoel,Jurgen Kosel

doi:10.1038/s41528-021-00100-4

By Altynay Kaidarova, Wenhao Liu + Show 5 more

Open Access

https://doi.org/10.1038/s41528-021-00100-4

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Abstract

Graphene has shown considerable potential for sensing magnetic fields based on the Hall Effect, due to its high carrier mobility, low sheet carrier density, and low-temperature dependence. However, the cost of graphene in comparison to conventional materials has meant that its uptake in electronic manufacturing has been slow. To lower technological barriers and bring more widespread adoption of graphene Hall sensors, we are using a one-step laser scribing process that does not rely on multiple steps, toxic chemicals, and subsequent treatments. Laser-scribed graphene Hall sensors offer a linear response to magnetic fields with a normalized sensitivity of ~1.12 V/AT. They also exhibit a low constant noise voltage floor of ~ 50 nV/sqrt {{mathrm{Hz}}} for a bias current of 100 µA at room temperature, which is comparable with state-of-the-art low-noise Hall sensors. The sensors combine a high bendability, come with high robustness and operating temperatures up to 400 °C. They enable device ideas in various areas, for instance, soft robotics. As an example, we combined a laser-scribed graphene sensor with a deformable elastomer and flexible magnet to realize low-cost, compliant, and customizable tactile sensors.

Highlights

INTRODUCTIONThe paradigm for technological advancements for emerging electronics is moving toward user-friendly solutions that includes ease of use, wearing sensation, portability, and human sensibility
The paradigm for technological advancements for emerging electronics is moving toward user-friendly solutions that includes ease of use, wearing sensation, portability, and human sensibility.The application potential of wearable and soft devices, electronic and e-skins has been, of great interest during the past decades[1,2]
Flexible Hall-effect sensors have been realized in different ways, including by stacked thin films, such as bismuth[9], permalloy[5], and graphene[10], deposited on a flexible substrate, such as polyimide (PI), polyethylenterephthalat, and polyetheretherketone (PEEK)

Summary

INTRODUCTION

The paradigm for technological advancements for emerging electronics is moving toward user-friendly solutions that includes ease of use, wearing sensation, portability, and human sensibility. Magnetic sensing capabilities, integrated into flexible substrates, can provide unique properties, enabling to sense displacement, orientation, proximity, etc.[3,4,5,6,7]. CMOS-based Hall sensors are the most commonly utlised magnetic-field solid-state sensors, mainly due to low-cost production and compatibility with standard microelectronic processes (see Supplementary Table 1)[8]. Flexible Hall-effect sensors have been realized in different ways, including by stacked thin films, such as bismuth[9], permalloy[5], and graphene[10], deposited on a flexible substrate, such as polyimide (PI), polyethylenterephthalat, and polyetheretherketone (PEEK)

AND DISCUSSION

Findings

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