Pressure sensing of liquid metal-based fiber arrays

Lei Wang,Junheng Fu,Jing Liu,Feng Zhao

doi:10.1063/5.0041355

Lei Wang, Junheng Fu + Show 2 more

Open Access

https://doi.org/10.1063/5.0041355

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Abstract

The GaIn based room temperature liquid metal (LM) is a potential material for sensing applications due to its good fluidity and excellent conductivity. The change in volume or shape substantially modifies the LM electrical properties, especially in the case of limited volume. In this study, we coated LM on fiber arrays to establish a relationship between external stress and the electrical signal. The external force applied to the flexible fibers induces their deformation, changing the electrical signal. We recorded this change experimentally and established the relationship between the stress and the electrical signal. The sensitivity can be adjusted by the elastic module and length of fibers. Fiber arrays of different lengths may cover a wide range of stress values. This novel design has potential applications in the fields of sensing and stretchable electronics.

Highlights

Pressure sensors generally exist in nature.1–3 Insects’ bristles, cats’ whiskers, and human skin can accurately perceive any changes in the environment, transduce the external stimuli into physiological signals, and provide highly sensitive strain and pressure sensors (Fig. S1 in the supplementary material).4,5 This inspired the development of fibers with pressure sensing functions to mimic the sensing function of the insects’ bristles
Once the fiber surface is coated with liquid metal (LM) via the dip-coating method, the fiber exhibits excellent conductivity
The results show that the LM-coated fiber cannot be pulled out from the LM solution, yielding enhanced adhesion between the fiber and LM

Summary

INTRODUCTION

Pressure sensors generally exist in nature. Insects’ bristles, cats’ whiskers, and human skin can accurately perceive any changes in the environment, transduce the external stimuli into physiological signals, and provide highly sensitive strain and pressure sensors (Fig. S1 in the supplementary material). This inspired the development of fibers with pressure sensing functions to mimic the sensing function of the insects’ bristles. Insects’ bristles, cats’ whiskers, and human skin can accurately perceive any changes in the environment, transduce the external stimuli into physiological signals, and provide highly sensitive strain and pressure sensors (Fig. S1 in the supplementary material).. Insects’ bristles, cats’ whiskers, and human skin can accurately perceive any changes in the environment, transduce the external stimuli into physiological signals, and provide highly sensitive strain and pressure sensors (Fig. S1 in the supplementary material).4,5 This inspired the development of fibers with pressure sensing functions to mimic the sensing function of the insects’ bristles. Pressure sensors must exhibit flexibility, shape memory, fast recovery, and a large sensing range to achieve stable and reliable functions.. The GaIn-based liquid metal (LM) exhibits good fluidity and high conductivity, which enables potential electrical applications.. The large surface tension of LM limits its use. It is of the highest priority to find a surface that could enhance the interfacial adhesion between the solid base and LM.

Preparation of the LM-based conductive fibers

RESULTS AND DISCUSSION

CONCLUSIONS