Fig. 2: Conductor/semiconductor and conductor/semiconductor/conductor bioelectronic interfaces.

a–c Representative examples of conductor/semiconductor devices for neuromodulation. a Scanning electron microscopy image of a fully organic retinal prosthesis for artificial vision. Implantation in the subretinal space restored visual functions in blind rats. Image reprinted by permission from Springer Nature³². b Photovoltaic interface based on aluminium antimonide nanocrystals for the capacitive stimulation of primary neurons. The scale bar in the insert is 200 nm. Image adapted under the Creative Commons Attribution (CC-BY) license⁷. c Sketch of a quantum dot nano-heterojunction allowing strong photocapacitive current generation. Image adapted under the Creative Commons Attribution (CC-BY) license³⁴. d, e Representative examples of conductor/semiconductor/conductor devices for neuromodulation. d The image shows the POLYRETINA device for artificial vision. Image adapted under the Creative Commons Attribution (CC-BY) license³⁷. e Sketch of a photovoltaic patch exploited for wound healing. Image adapted under the Creative Commons Attribution (CC-BY) license¹¹. In each panel, the dashed box shows a layer-by-layer sketch of the device and the putative main neuromodulation mechanisms.