A Wavy-Structured Highly Stretchable Thermoelectric Generator with Stable Energy Output and Self-Rescuing Capability

Abstract

Thermoelectric generators (TEGs) demonstrate great potential for flexible and wearable electronics due to the direct electrical energy harvesting from waste heat. Good wearability requires high mechanical flexibility and preferable stretchability, while current TEGs are primarily developed with rigid or non-stretchable components, which cannot well conform to human skin or accommodate human motions, thus hindering further applications. Herein, a wavy architecture is proposed for the fabrication of stretchable TEGs, where a stretchable and self-healable hydrogel is employed as device substrate, and intrinsically flexible highperformance TE films are attached to form wavy morphologies. The wavy-structured TEG can be readily stretched to 300%, and in the meantime can sustain a stable energy output with more than 90% TE performance retained, which outperforms most of the reported state-of-the-art TE materials and TEGs. It also demonstrates a desired device-level self-rescuing capability originated from the effective self-healing of the hydrogel and the wavy structure of TE legs, thereby providing persistent energy supply upon injuries or damages. This work offers a promising approach for the design of next-generation stretchable and wearable TEGs.

Highly Stretchable, Fast Self-Healing, and Waterproof Fluorinated Copolymer Ionogels with Selectively Enriched Ionic Liquids for Human-Motion Detection

“…Upon the addition of fluorine-rich [BMIM]­[TFSI], N 1s and S 2p spectra in the SFCI-2 were introduced. The N 1s spectra can be deconvoluted into two peaks centered at 400.7 and 398.1 eV (Figure S8b), corresponding to the N atoms in N + of imidazole rings ,, and S–N–S of anions of fluorine-rich ILs, respectively. Also, the S 2p spectra attributed to fluorine-rich ILs were deconvoluted into 2p 1/2 and 2p 3/2 peaks (Figure S8c).…”

Stretchable Thermoelectrics: Strategies, Performances, and Applications

“…Liu et al employed a stretchable and self-healable hydrogel as the substrate and combined a flexible thermoelectric film with the prestrained hydrogel. [79] When the prestrain was released, a wrinkle structure formed on the flexible thermoelectric film. The molecular chains in hydrogel interacted with each other by dynamic hydrogen bonding, which endows the thermoelectric generator desirable stretchability (300% tensile strain without thermoelectric performance injured) and self-healing characteristics.…”

Thermo-electrochemical cells for heat to electricity conversion: from mechanisms, materials, strategies to applications

“…To this end, thermoelectric generators (TEGs) presented in Fig. 1B have been widely investigated in recent decades owing to their capability of converting heat to electricity directly, [10][11][12][13] and vice versa. Compared to other energy generators, TEGs can work with no moving parts and no emissions, and continuously output power.…”