Bioelectricity Inspired Polymer Electrolyte Membranes for Sensing and Energy Harvesting Applications

Résumé du livre

Some living cells are known to generate bioelectricity by manipulating the ion concentration gradient across the cell membrane via passive and active ion transports, which are controlled by ion gates and pumps. This process involves polarization and depolarization of the cell membrane, resulting in electrical potential often called membrane potential. Neuron cells utilize such ionic polarization process to send electrical signals for communication and control of body parts. On the other hand, electroplaques in electric eels can store sizable electrical energy and release it on demand for defending and hunting. A similar ionic polarization potential can be generated via bending deformation (as a means of exerting a pressure (stress) gradient) of polymer electrolyte membrane (PEM), which was originally developed as ion conducting solid medium for solid-state Li-ion batteries. This is the motivation of the present dissertation to explore the novel flexoelectric effect in the aforementioned solid-state PEM by subjecting it to mechanical deformation. A plausible mechanism has been proposed to explain the mechano-electrical transduction in the above solid PEMs, wherein ionic polarization occurred as a result of ion diffusion under pressure (stress) gradient. The flexoelectric coefficient has been measured to be as high as ~300 [micron]C/m, which is several orders of magnitude higher relative to those of other flexoelectric materials hitherto reported in literature. These new and fascinating features found in the present solid PEM system open up a new avenue of polymeric energy materials for diverse applications such as flexible sensor and energy harvesting devices.