A wireless, solar-powered, optoelectronic system for spatial restriction-free long-term optogenetic neuromodulations

Abstract

Numerous wireless optogenetic systems have been reported for practical tether-free optogenetics in freely moving animals. However, most devices rely on battery-powered or coil-powered systems requiring periodic battery replacement or bulky, high-cost charging equipment with delicate antenna design. This leads to spatiotemporal constraints, such as limited experimental duration due to battery life or animals’ restricted movement within specific areas to maintain wireless power transmission. In this study, we present a wireless, solar-powered, flexible optoelectronic device for neuromodulation of the complete freely behaving subject. This device provides chronic operation without battery replacement or other external settings including impedance matching technique and radio frequency generators. Our device uses high-efficiency, thin InGaP/GaAs tandem flexible photovoltaics to harvest energy from various light sources, which powers Bluetooth system to facilitate long-term, on-demand use. Observation of sustained locomotion behaviors for a month in mice via secondary motor cortex area stimulation demonstrates the notable capabilities of our device, highlighting its potential for space-free neuromodulating applications.

Functional nanotransducer-mediated wireless neural modulation techniques

“…The author demonstrated the PT-UCNP-B-mediated reversible excitation and inhibition to light-gated ChR2 channel and voltage-gated KCNQ1 channels under 980 and 808 nm irradiation in vitro, respectively. Furthermore, the PT-UCNP-B, after injected in the ChR2-expressing lateral hypothalamus region, also achieved bidirectional deep-brain modulation of feeding behavior in mice under tether-free 980 or 808 nm irradiation (figures 3(d) and (e)) (Park et al 2023). Thus, the advanced light nanomaterial platform PT-UCNP-B/G opens up the possibility of utilizing both photostimulation and thermo-stimulation for bidirectional neuromodulation.…”

“…Considering the heat desensitization of TRPV1, the photothermal stimulation temperature and duration should also be precisely regulated to reduce the side effects of photothermal overheating (Luo et al 2019). The above-mentioned photothermal agent-modified UCNPs in the previous section can achieve simultaneous light-mediated and photothermal neuromodulation under NIR light at 980 nm and 808 nm, respectively (Park et al 2023). This nanotechnology creates a new possibility to overcome the limits of photothermal neuromodulation by providing a double-effect synergistic strategy based on optogenetics and thermogenetics.…”

“…Additionally, implanting fibers into multiple brain regions is too invasive to implement multi-region stimuli for neuromodulation, which may lead to adverse consequences during behavioral studies of the tethered mice, especially for socially interacting animals. There is an urgent need to develop novel wireless optogenetic techniques (Li et al 2021, Park et al 2023.…”

Novel fabrication techniques for ultra-thin silicon based flexible electronics

“…<a few hundred nanometers), enhancing the quality and performance of bioelectronics. Thus, the excellent biocompatibility and flexibility of Si make it for wearable [74][75][76][77], bio-implant [78][79][80][81], and biomimetic applications by using suitable structures and characteristics [82][83][84]. Furthermore, flexible Si electronics have led to advancements in the soft robotic field, improving stability, adaptability, and manipulation accuracy [85][86][87].…”