Gong, Z., Suwardi, A., & Cao, J. (2025). Electricity Generation From Ambient Water Evaporation in the Absence of Sunlight via PVA‐Based Porous Hydrogels. Advanced Functional Materials, 36(6). Portico. https://doi.org/10.1002/adfm.202423371
Abstract:
In the current era where electronics and technologies are getting smaller in size, off-grid and battery-free features are getting increasingly sought after. This motivates innovation in ambient energy harvesting from light, heat, and mechanical sources. Among these technologies, hydrovoltaics has emerged as a promising source of electricity by harvesting energy from ubiquitous water evaporation. However, the power densities of hydrovoltaics are so far limited to the order of hundreds of mW cm⁻2. In this work, a porous polyvinyl alcohol (PVA) hydrogel in combination with a thermoelectric generator (TEG) is devised to directly capture energy from water evaporation. It is found that under moderate environmental conditions with relative humidity (RH) of 40%, temperature of 26 °C, and mild wind speed of 2.8 m s−1, a temperature gradient (ΔTTEG) of ≈2 °C is established across the TEG. This gives rise to 1.71 mW of power output, which is equivalent to 1.02 W m−2 power density. This is more than 3 fold higher than traditional hydrovoltaics. This work opens a pathway for further investigation into scavenging electricity from water evaporation.
License type:
Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Funding Info:
This research / project is supported by the A*STAR - e-Asia Joint Research Program
Grant Reference no. : R22I1IR053
This research / project is supported by the National Research Foundation - LCER Phase 2 Emerging Technology Grant Call (ETGC)
Grant Reference no. : U2411D4011