Room-Temperature Self-Repairable Yet Mechanically Robust Elastomeric Triboelectric Nanogenerators Enabled by a Fast-Reversible Dual-Dynamic Network

Abstract

Self-healable polymers hold great promise for durable triboelectric nanogenerators (TENGs) in sustainable energy harvesting. Incorporating dynamic bonds into polymers can enhance the self-healing, whereas mechanical properties are usually sacrificed for rapid network rearrangement. Here, we present a straightforward strategy to fabricate room-temperature self-repairable yet mechanically robust TENGs based on dualdynamic networks of disulfide-containing poly(urethane-urea) (S-PUU) elastomers. By incorporating aromatic disulfides featuring electron-donating groups (amines) into the hard segments of polyurethane, we establish dual-dynamic networks consisting of reversible disulfide (S−S) and hydrogen bonds. The coexistence of these double dynamic bond exchanges, facilitated by the activating effect of amine groups, triggers the fast reversibility of the S-PUU networks with relaxation times as short as ∼7.8 s at room temperature. While achieving rapid self-repairability, S-PUUs simultaneously exhibit significant improvement in mechanical strength and toughness with effective energy dissipation, arising from the synergy among interchain cross-linking, rigid diphenyl inclusion, and the constant breaking−regrouping of reversible bonds. The rapid rearrangement of dual-dynamic networks enables TENGs to achieve a high self-healing efficiency of up to 96% at room temperature, without external heating or catalysts. In addition, the outstanding mechanical robustness and recoverability endow the device with a remarkably durable electricity-generating performance. Moreover, the versatile nanogenerators with favorable stretchability allow effective mechanical energy harvesting and self-powered stimulus detection in both pressing and stretching modes. This work would inspire the fabrication of TENGs combining mild-condition self-repairability and excellent mechanical performance for durable and sustainable energy harvesting.

Room-Temperature Dynamic and Creep-Resistant Covalent Adaptive Networks via Phase-Locked Benzimidazole Urea Bonds: Toward Recyclable Elastomers for Wearable Electronic Devices

“…Figure f,g illustrates the dissociation process of R → P. The process of R dissociating to isocyanate involves an activation energy of 24.01 kcal/mol, occurring through a six-membered ring transition state. This low activation energy value confirms the feasibility of SUBI moiety dissociation at room temperature . Additionally, the activation energy for the reversible reaction (P → R) is approximately 10 kcal/mol, suggesting the rapid formation of SUBI at room temperature.…”