Salinity power generation based biocompatible bacterial cellulose/MXene membrane for biological power source

Powering implanted medical devices (IMDs) is still a challenge since the biological system requires biocompatible, stable, and miniaturized electrical power sources. Making use of the salinity gradient is an attractive and efficient way to generate power. Here, we demonstrate the ion-channel-mimetic negatively charged bacterial cellulose (NBC)/MXene nanofluidic membrane as an osmotic nanopower generator. The introduction of NBC nanofibers into MXene nanosheets brings space charge and enhances ion flux. Considering the in vivo application, saline gelatin hydrogels are used as solid electrolytes for the first time. Benefiting from the combination of one-dimensional (1D) nanofibers and two-dimensional (2D) MXene sheets, a power density of 2.58 W m−2 is obtained under a 100-fold concentration gradient of solid electrolyte. This work demonstrates that salinity energy conversion can also be achieved using solid electrolytes. Moreover, the results of in vitro and in vivo evaluations demonstrate the good biocompatibility of the hybrid membranes. The high-performance osmotic energy conversion and good biocompatibility of the NBC/MXene membrane make it a promising tissue-integrated battery for powering implanted medical devices.