Fiber‐Based Energy Conversion Devices for Human‐Body Energy Harvesting

Abstract

body is actually a tremendous storehouse of energy that is generated from body heat and motion. [15][16][17][18][19] Power generation from breathing, heating, blood transport, arm motion, typing, and walking could reach to over 100 W for a 68 kg adult's daily activities (Figure 1). [20] Thus, converting 1% of power from the human body may be enough to support the work of most portable electronics.In the past two decades, researchers have developed several energy conversion devices based on piezoelectricity, electrostaticity, triboelectricity, or thermoelectricity that can directly harvest the mechanical or thermal energy and convert it into electric energy (these conversion devices are so-called nanogenerators (NGs)). [21][22][23][24][25] The first nanogenerator (NG) based on ZnO was invented by Prof. Wang in 2006; after that, various NGs were developed to harvest the mechanical or thermal energy with the output performance increasing gradually. [26] These NGs are easy-to-construct flexible devices since most materials for these devices are polymers and nanomaterials. Generally, the flexible devices assembled by film materials can be stretchable and bendable in one direction. But their lack of air-permeability, poor 3D deformation, and low damage tolerance limit their application, especially for wearable electronics. Therefore, fiberbased energy conversion devices have been designed. [27] These fiber-based devices can also be knitted to yarn or fabric in the clothing system to build up a large area electronic system. [28,29] The energy generation and internal charging can be realized by means of a self-powered system that harvests the energy from natural sources around the human body to sustain the wearable electronics. [30][31][32] The search for functional materials that possess good conversion efficiency, as well as great mechanical and environmental stability, combined with a novel device design might push these devices to meet the requirement of a practical application. In the past decade, numerous contributions have been offered to improve the performance of fiber-based energy conversion devices (FBECD) and extend its application. This review specifically summarizes FBECD with different energy conversion mechanisms including piezoelectricity, electrostaticity, triboelectricity, and thermoelectricity in recent processes (Figure 2). The functional materials, fiber fabrication techniques, and device design strategies for different classes of FBECDs are covered in the article. We also introduce an overview of the fiber-based self-powered system and sensors and Following the rapid development of lightweight and flexible smart electronic products, providing energy for these electronics has become a hot research topic. The human body produces considerable mechanical and thermal energy during daily activities, which could be used to power most wearable electronics. In this context, fiber-based energy conversion devices (FBECD) are proposed as candidates for effective conversion of human-body energy into electricity...

A Machine‐Fabricated 3D Honeycomb‐Structured Flame‐Retardant Triboelectric Fabric for Fire Escape and Rescue

“…[ 14 ] First, for fabric triboelectric nanogenerators (F‐TENGs) that are manufactured by dip coating of functional materials on the entire fabric, the fabric is usually of high hardness and extremely poor permeability, which severely affect their wearing comfort. [ 15 ] Second, multilayer‐structured F‐TENGs have typically been prepared via complicated procedures, resulting in the devices being bulky and rigid, [ 16 ] which is neither propitious to harvest energy from the subtle movements of the human body in routine life, nor suitable for soft sensing and detection. [ 17 ] In this concern, fabricating the F‐TENG by weaving machine from continuous TENG yarn which could guarantee its permeability, flexibility, and comfort is important to solve the aforementioned problems.…”

Semiconductor glass with superior flexibility and high room temperature thermoelectric performance

“…Wearable electronic devices integrating with the natural environment and human experience have been receiving increasing attention (1). Energy conversion devices that can convert ambient energy into electricity are eagerly desired for self-powered wearable devices.…”

Self‐Actuating Electrocaloric Cooling Fibers

“…The fiber‐shaped devices could be woven into flexible textiles, films, and 3D structures. [ 18,19 ] Furthermore, a fiber structure may be conveniently attached to devices of small sizes, conformed on complicated surfaces, or inserted into narrow places. [ 18 ] Here, we designed EC fibers comprised of thin conductive wire core, P(VDF‐TrFE‐CFE) dielectric layer, and SWCNTs outer layer for active heating and cooling controls.…”

“…[ 18,19 ] Furthermore, a fiber structure may be conveniently attached to devices of small sizes, conformed on complicated surfaces, or inserted into narrow places. [ 18 ] Here, we designed EC fibers comprised of thin conductive wire core, P(VDF‐TrFE‐CFE) dielectric layer, and SWCNTs outer layer for active heating and cooling controls. Self‐actuation of the fiber was observed instantaneously with the EC operation, which transports the fiber between two different locations, analogous to a motor in a refrigerator but without consuming much extra energy.…”