Liquid Metal Based Flexible and Implantable Biosensors

Abstract

Biosensors are the core elements for obtaining significant physiological information from living organisms. To better sense life information, flexible biosensors and implantable sensors that are highly compatible with organisms are favored by researchers. Moreover, materials for preparing a new generation of flexible sensors have also received attention. Liquid metal is a liquid-state metallic material with a low melting point at or around room temperature. Owing to its high electrical conductivity, low toxicity, and superior fluidity, liquid metal is emerging as a highly desirable candidate in biosensors. This paper is dedicated to reviewing state-of-the-art applications in biosensors that are expounded from seven aspects, including pressure sensor, strain sensor, gas sensor, temperature sensor, electrical sensor, optical sensor, and multifunctional sensor, respectively. The fundamental scientific and technological challenges lying behind these recommendations are outlined. Finally, the perspective of liquid metal-based biosensors is present, which stimulates the upcoming design of biosensors.

Nacre‐Inspired, Liquid Metal‐Based Ultrasensitive Electronic Skin by Spatially Regulated Cracking Strategy

“…Although liquid metal and its composites have been reported for the sensing of mechanical stimuli, its applications are largely limited due to the insufficient sensitivity, which has been pointed out by many researchers. [ 14–17 ] To date, the sensitivity of liquid metal‐based strain sensors is still orders of magnitudes lower than the reported state‐of‐art counterparts ( Figure g). The development of highly sensitive, liquid metal‐based sensors will benefit more skin‐integrated sensing scenarios requiring high sensitivity, such as platelet contraction and radial artery pulse detection.…”

Soft Devices for High-Resolution Neuro-Stimulation: The Interplay Between Low-Rigidity and Resolution

“…Liquid metals are an emerging material gaining interest in applications for biosensors in wearable and implantable devices ( 284 ). Liu et al extensively researched this field and suggest liquid metals as a preferable alternative that benefit from low mechanical mismatch and low corrosion ( 285 ).…”

Flexible Tactile Sensing Microfibers Based On Liquid Metals

“… 12 − 21 To the best of our knowledge, the research of LM composite fibers is in the initial stage. 12 , 22 − 26 Furthermore, there has been a steady growth of research papers in this field, 27 − 30 reporting various LM composite fiber sensors, including self-powered sensors, 31 implantable biosensors, 32 selective biosensors, 33 strain sensors, 34 and capacitive sensors. 35 For example, Wu previously reported the LM microfibers as self-powered sensors.…”