A Liquid–Solid Contact Electrification Based All‐Optical Liquid Flow Sensor for Microfluidic Analysis in Biomedical Applications

Abstract

Liquid flow sensor is an important component of the microfluidic system for analytical science and biomedical systems. However, traditional microfluidic systems are complex in structure, costly, bulky, and generate environmental pollutants. Herein, a novel and high‐performance self‐powered all‐optical liquid flow sensor (ALFS) based on triboelectrification‐induced electroluminescence (TIEL) is proposed. The TIEL signal is self‐generated in real time through contact electrification between a polymer–fluid–air surface and moving fluid. Moreover, the amplitude and time span of the electric field can be swiftly altered by adjusting the bottom grid electrode layer with an appropriate geometric design, so that a high sensitivity of 0.089 s mm–1 and an extremely low flow velocity limit of 1 mm s–1 can be achieved. The velocity, volume, and composition of the liquid flow can be obtained either by observation or through optical information extraction from data analysis software. Furthermore, the ALFS can be incorporated into an infusion monitor and a microfluidic chip for biomedical applications. This study proposes not only an innovative method for liquid flow monitoring but also a new rationale of coupling triboelectrification into the microfluidic system design, which potentially has a wide range of applications in the medical, biological, and industrial fields.

Contact Electrification Behaviors of Solid–Liquid Interface: Regulation, Mechanisms, and Applications

“…The TIEL signal is self‐generated in real time through contact electrification between a polymer–fluid–air surface and moving fluid. [ 66 ] The PTFE ultrafiltration membrane is used as the friction layer to absorb wave energy through water in order to achieve the self‐power supply of the cathodic protection system in the maritime environment and construct a novel form of liquid–solid TENG array combination. [ 67 ] Solid–liquid TENGs may protect metals from all types of weather, and parallel or series circuit design can result in more effective cathodic protection of metal materials.…”

“…Sensor: Reproduced with permission. [ 66 ] Copyright 2022, Wiley‐VCH. Wireless signal: Reproduced with permission [17b] .…”

Persistent triboelectrification-induced electroluminescence for self-powered all-optical wireless user identification and multi-mode anti-counterfeiting

“…Moreover, with the recent advancements in TIEL technologies, it is evident that the regulation of the amplitude value and time interval of dynamic motion can contribute to variations in the electric field, which provides two effective approaches to achieve considerably high TIEL intensity and an insight into the design of TIEL materials. 15,18,27,28 However, the reported TIELs are generally radiated in all directions in free space, which severely restricts the collection and detection of photons. In terms of developing design theories for TIEL materials toward outstanding optical performance, it remains a tough challenge to impose control on the radiation characteristics of TIEL.…”

“…8–12 It has been found that this TIEL phenomenon is characterized by the non-destructive property, high-stress responsivity, and a low stress-threshold value (far exceeding that of conventional ML), which make it a promising candidate for developing intelligent optical systems. 13–17 Until now, most of the existing ML or TIEL materials are intrinsically capable of exhibiting instantaneous luminescence with responsiveness in the sub-millisecond (ms) level, which provides an effective solution for real-time visualized sensing. 18–20 However, despite these achievements, complex equipment is still required for the capture of transient-light signals with complete information.…”

“…[8][9][10][11][12] It has been found that this TIEL phenomenon is characterized by the non-destructive property, high-stress responsivity, and a low stress-threshold value (far exceeding that of conventional ML), which make it a promising candidate for developing intelligent optical systems. [13][14][15][16][17] Until now, most of the existing ML or TIEL materials are intrinsically…”