fig1

Figure 1. Two examples of low-grade energy of moisture and low-grade heat co-existing in our living environment. Body heat and moisture from breathing, sweating, cutaneous transpiration, etc., can be harnessed for power generation based on hydrogel materials. Exhaust heat from air conditioners and relative humidity differences between indoor and outdoor environments can also be utilized to produce electricity through hydrogel materials. (Ionic species at oxidized state and reduced state are expressed as Ox and Red, respectively).