Integrated Mechano-Electrochemical Harvesting Fiber and Thermally Responsive Artificial Muscle for Self-Powered Temperature–Strain Dual-Parameter Sensor

Abstract

Significant progress in healthcare fields around the world has inspired us to develop a wearable strain–temperature sensor that can monitor biomedical signals in daily life. This novel self-powered temperature–strain dual-parameter sensor comprises a mechano-electrochemical harvester (MEH) and a thermally responsive artificial muscle (TAM). The MEHTAM system generates electricity from strain and thermal fluctuations. In addition, the sensor is comfortable to wear, owing to its stretchability (>100%), softness (<3 MPa), and one-dimensional fibers (diameter 230 μm). The MEH induces a change in the electrochemical capacitance, resulting in an electrical signal under applied strain (34 μA/m) and stress (20 μA/(m·MPa)). The TAM can be used as a mechanical temperature sensor, because the tensile stroke responds linearly to changes in temperature. As the harvester and artificial muscle are combined, the MEHTAM system generates electricity, owing to external and internal mechanical stimuli caused by muscle contractions as a response to temperature changes. The MEHTAM system that we have developed—a self-powered, strain–temperature dual-parameter sensor that is soft, stretchable, and fiber-shaped—is an interesting candidate for the production of comfortable, wearable, dual-parameter sensors.

Hierarchically Plied Mechano-Electrochemical Energy Harvesting Using a Scalable Kinematic Sensing Textile Woven from a Graphene-Coated Commercial Cotton Yarn

“…With the emergence of a ubiquitous healthcare system, the development of new technology has come to the fore of medical research, and wearable strain-sensing systems that can detect the state and movement of the human body have garnered significant attention in recent years. − In previous studies, the strain was detected using a strain gauge, which captures strain-induced resistance changes. − However, an external energy source is required to operate the gauge, and as a result, such a sensing system is generally complex and bulky. , To simplify wearable sensing systems, a self-powered strain sensor based on a mechanical harvester, which produces electrical energy from mechanical energy, has been developed. , A triboelectric generator has also been proposed for a self-powered strain sensor. , However, the efficiency of these previously reported self-powered wearable strain sensors degrades under humidity and at high temperatures (i.e., ambient environment), which severely restricts their application in real-life scenarios. Moreover, although piezoelectric generators act as self-powered strain sensors and measure strain under various external environmental conditions, − they generate a low current output for low-frequency motion (below 2 Hz). , Consequently, their applicability as human motion monitoring systems is limited.…”

“…4,8 To simplify wearable sensing systems, a self-powered strain sensor based on a mechanical harvester, which produces electrical energy from mechanical energy, has been developed. 9,10 A triboelectric generator has also been proposed for a self-powered strain sensor. 11,12 However, the efficiency of these previously reported self-powered wearable strain sensors degrades under humidity and at high temperatures (i.e., ambient environment), which severely restricts their application in real-life scenarios.…”