Stretchable Thermoelectric Fibers with Three-Dimensional Interconnected Porous Network for Low-Grade Body Heat Energy Harvesting.

Electricity generation from body heat has garnered significant interest as a sustainable power source for wearable bioelectronics. In this work, we report stretchable n-type thermoelectric fibers based on the hybrid of Ti3C2Tx MXene nanoflakes and polyurethane (MP) through a wet-spinning process. The proposed fibers are designed with a 3D interconnected porous network to achieve satisfactory electrical conductivity (σ), thermal conductivity (κ), and stretchability simultaneously. We systematically optimize the thermoelectric and mechanical traits of the MP fibers and the MP-60 (with 60 wt % MXene content) exhibits a high σ of 1.25 × 103 S m-1, an n-type Seebeck coefficient of -8.3 µV K-1, and a notably low κ of 0.19 W m-1 K-1. Additionally, the MP-60 fibers possess great stretchability and mechanical strength with a tensile strain of 434% and a breaking stress of 11.8 MPa. Toward practical application, a textile thermoelectric generator is constructed based on the MP-60 fibers and achieves a voltage of 3.6 mV with a temperature gradient between the body skin and ambient environment, highlighting the enormous potential of low-grade body heat energy harvesting.

Retirement is not the end of the road: Essentialist beliefs about aging moderate the association between future time perspective and retirement adjustment.

Objective: The present study aims to investigate whether changes in future time perspective could influence individual's retirement process and adjustment. Moreover, we would also like to test moderation effect of essentialist beliefs about aging on the association between changes in future time perspective and retirement adjustment. Method: 201 participants were recruited 3 months before retirement and followed for 6 months. Future time perspective was measured before and after retirement. Essentialist beliefs about aging was measured before retirement. Other demographics as well as life satisfaction were also measured as covariates. Results: Multiple regressions were conducted, and the results revealed that (1) retirement could lead to limited future time perspective, but individual differences regarding the influence of retirement on future time perspective also exists; (2) increase in future time perspective was positively associated with retirement adjustment; and moreover, (3) such association was moderated by fixed views of essentialist beliefs, such that retirees holding a more fixed view of essentialist beliefs about aging exhibited a stronger association between future time perspective change and retirement adjustment, while those who held less fixed view of essentialist beliefs about aging did not show such association. Discussion: The present study contributes to the literature by showing that future time perspective could be influence by retirement, and such changes could in turn further impact adjustment. And the association between changes in future time perspective and retirement adjustment was only effective among retirees holding more fixed views of essentialist beliefs about aging. Findings would also provide important practical implications to improve retirement adjustment. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-023-04731-w.