Biophysical Sensors Based on Triboelectric Nanogenerators

Abstract

Triboelectric nanogenerators (TENGs) can not only collect mechanical energy around or inside the human body and convert it into electricity but also help monitor our body and the world by providing interpretable electrical signals during energy conversion, thus emerging as an innovative medical solution for both daily health monitoring and clinical treatment and bringing great convenience. This review tries to introduce the latest technological progress of TENGs for applications in biophysical sensors, where a TENG functions as a either a sensor or a power source, and in some cases, as both parts of a self-powered sensor system. From this perspective, this review begins from the fundamental working principles and then concisely illustrates the recent progress of TENGs given structural design, surface modification, and materials selection toward output enhancement and medical application flexibility. After this, the medical applications of TENGs in respiratory status, cardiovascular disease, and human rehabilitation are covered in detail, in the form of either textile or implantable parts for pacemakers, nerve stimulators, and nerve prostheses. In addition, the application of TENGs in driving third-party medical treatment systems is introduced. Finally, shortcomings and challenges in TENG-based biophysical sensors are highlighted, aiming to provide deeper insight into TENG-based medical solutions for the development of TENG-based self-powered electronics with higher performance for practical applications.

Recent progress towards smart transportation systems using triboelectric nanogenerators

“…Because CS are simple structures that are straightforward to construct, they are employed in a wide range of applications. CS tribo-pairs are frequently designed with an arch-shaped structure, spacer structure, or spring-assisted structure due to the requirement for space between their surfaces [39]. • Lateral sliding mode (LS): The electricity generation mechanism of LS is like that of CS; however, LS involves horizontal sliding between two materials [40].…”

Ferroelectric Material in Triboelectric Nanogenerator

“…Originally developed for effectively changing movement energy into electric energy using electrostatic coupling and the friction electric effect [ 75 ], TENGs are a new class of energy harvesting device that can now be used as a sensor [ 76 ] and a power source [ 77 ] to create self-powered systems for a wide variety of applications. The triboelectric effect describes the emergence of electric charges when two dissimilar materials with varying surface electron affinities come into contact [ 78 ]. Friction causes the surfaces of the two materials to separate, producing different electrical potentials [ 79 ].…”

A Review on the Progress in Core‐Spun Yarns (CSYs) Based Textile TENGs for Real‐Time Energy Generation, Capture and Sensing

“…Hence T-TENGs have the capabilities of acting as ion-sensitive electrochemical sensors, [102][103][104] displacement, acceleration sensors, [105] humidity sensors, [106] temperature sensors, [107,108] biomedical and other sensors. [109][110][111][112] However, to date, as already discussed T-TENGs are not capable of producing high power densities that are equivalent to those in batteries, which limits their use in wearable self-powered applications. Moreover, T-TENGs require consistent and predictable mechanical inputs to generate constant output, which may not always be available in real-time wearable conditions.…”

“…Hence future research needs to focus on developing CSYs T‐TENG‐based sensors with high efficacy for a variety of sensing applications such as; ion‐sensitive electrochemical, displacement, acceleration, humidity and temperature. [ 109 , 110 , 111 , 112 ] If this is achieved, it will enable the use of CSYs T‐TENGs with total autonomy combining energy and sensing from the same device in modern IoT‐enabled smart wearable devices and garments.…”