A number of research attempts to understand and modulate sensory and motor skills that are beyond the capability of humans have been underway. They have mainly been expounded in rodent models, where numerous reports of controlling movement to reach target locations by brain stimulation have been achieved. However, in the case of birds, although basic research on movement control has been conducted, the brain nuclei that are triggering these movements have yet to be established. In order to fully control flight navigation in birds, the basic central nervous system involved in flight behavior should be understood comprehensively, and functional maps of the birds’ brains to study the possibility of flight control need to be clarified. Here, we established a stable stereotactic surgery to implant multi-wire electrode arrays and electrically stimulated several nuclei of the pigeon’s brain. A multi-channel electrode array and a wireless stimulation system were implanted in thirteen pigeons. The pigeons' flight trajectories on electrical stimulation of the cerebral nuclei were monitored and analyzed by a 3D motion tracking program to evaluate the behavioral change, and the exact stimulation site in the brain was confirmed by the postmortem histological examination. Among them, five pigeons were able to induce right and left body turns by stimulating the nuclei of the tractus occipito-mesencephalicus (OM), nucleus taeniae (TN), or nucleus rotundus (RT); the nuclei of tractus septo-mesencephalicus (TSM) or archistriatum ventrale (AV) were stimulated to induce flight aviation for flapping and take-off with five pigeons.

(1) Background: In this study, we introduce a manufacturable 32-channel cochlear electrode array. In contrast to conventional cochlear electrode arrays manufactured by manual processes that consist of electrode-wire welding, the placement of each electrode, and silicone molding over wired structures, the proposed cochlear electrode array is manufactured by semi-automated laser micro-structuring and a mass-produced layer-by-layer silicone deposition scheme similar to the semiconductor fabrication process. (2) Methods: The proposed 32-channel electrode array has 32 electrode contacts with a length of 24 mm and 0.75 mm spacing between contacts. The width of the electrode array is 0.45 mm at its apex and 0.8 mm at its base, and it has a three-layered arrangement consisting of a 32-channel electrode layer and two 16-lead wire layers. To assess its feasibility, we conducted an electrochemical evaluation, stiffness measurements, and insertion force measurements. (3) Results: The electrochemical impedance and charge storage capacity are 3.11 ± 0.89 kOhm at 1 kHz and 5.09 mC/cm2, respectively. The V/H ratio, which indicates how large the vertical stiffness is compared to the horizontal stiffness, is 1.26. The insertion force is 17.4 mN at 8 mm from the round window, and the maximum extraction force is 61.4 mN. (4) Conclusions: The results of the preliminary feasibility assessment of the proposed 32-channel cochlear electrode array are presented. After further assessments are performed, a 32-channel cochlear implant system consisting of the proposed 32-channel electrode array, 32-channel neural stimulation and recording IC, titanium-based hermetic package, and sound processor with wireless power and signal transmission coil will be completed.

We report a 4 V-class cathode of layered nickel-rich LiNi0.8Mn0.1Co0.1O2 (NMC811) for use in poly(ethylene oxide) (PEO)-based lithium polymer batteries. A semi-interpenetrating polymer network (semi-IPN) PEO-based solid polymer electrolyte (SPE) is prepared by the in situ thermal cross-linking of a precursor solution containing a lithium salt, poly(ethylene glycol) dimethyl ether as the plasticizer, and bisphenol A ethoxylate diacrylate as the cross-linker. Using the dual salts of lithium bis(trifluoromethane)sulfonamide and lithium bis(oxalate)borate (LiBOB), the formation of a dense and stable solid electrolyte interface on the Li-metal anode leads to reduced electrolyte decomposition and suppresses Li dendrite formation during cycling. Moreover, LiBOB provides an effective cathode–electrolyte interface, which efficiently protects the NMC811 particles from cracking. Consequently, the cycling performances of the NMC811-based lithium polymer batteries are significantly enhanced. At 45 °C, with a high loading density of the active material, the NMC811/SPE/Li-metal battery delivers a specific discharge capacity of 166 mAh g–1 at 0.1C. Furthermore, the capacity of the cell remains at 82% after 200 cycles at 0.5C. These outstanding results demonstrate the potential for the practical application of NMC811-based lithium polymer batteries with enhanced energy densities and safety profiles.