Tether-less implantable upconverting microscale light bulbs for deep brain neural stimulation and imaging

We demonstrate the design and fabrication of implantable micro-scale light “bulbs” comprising of parylene-encapsulated upconverting lanthanide-doped nanocrystals (absorbing near-infrared and emitting blue light) for non-invasive targeted optogenetic stimulation of local neuronal ensembles.