Summary In vivo optogenetics provides unique, powerful capabilities in the dissection of neural circuits implicated in neuropsychiatric disorders. Conventional hardware for such studies, however, physically tethers the experimental animal to an external light source limiting the range of possible experiments. Emerging wireless options offer important capabilities that avoid some of these limitations, but the current size, bulk, weight, and wireless area of coverage is often disadvantageous. Here, we present a simple but powerful setup based on wireless, near-field power transfer and miniaturized, thin flexible optoelectronic implants, for complete optical control in a variety of behavioral paradigms. The devices combine subdermal magnetic coil antennas connected to microscale, injectable LEDs, with the ability to operate at wavelengths ranging from ultraviolet to blue, green/yellow, and red. An external loop antenna allows robust, straightforward application in a multitude of behavioral apparatuses. The result is a readily mass-producible, user-friendly technology with broad potential for optogenetics applications.

Optogenetic methods to modulate cells and signaling pathways via targeted expression and activation of light-sensitive proteins have greatly accelerated the process of mapping complex neural circuits and defining their roles in physiological and pathological contexts. Recently demonstrated technologies based on injectable, microscale inorganic light-emitting diodes (μ-ILEDs) with wireless control and power delivery strategies offer important functionality in such experiments, by eliminating the external tethers associated with traditional fiber optic approaches. Existing wireless μ-ILED embodiments allow, however, illumination only at a single targeted region of the brain with a single optical wavelength and over spatial ranges of operation that are constrained by the radio frequency power transmission hardware. Here we report stretchable, multiresonance antennas and battery-free schemes for multichannel wireless operation of independently addressable, multicolor μ-ILEDs with fully implantable, miniaturized platforms. This advance, as demonstrated through in vitro and in vivo studies using thin, mechanically soft systems that separately control as many as three different μ-ILEDs, relies on specially designed stretchable antennas in which parallel capacitive coupling circuits yield several independent, well-separated operating frequencies, as verified through experimental and modeling results. When used in combination with active motion-tracking antenna arrays, these devices enable multichannel optogenetic research on complex behavioral responses in groups of animals over large areas at low levels of radio frequency power (<1 W). Studies of the regions of the brain that are involved in sleep arousal (locus coeruleus) and preference/aversion (nucleus accumbens) demonstrate the unique capabilities of these technologies.wireless optogenetics | stretchable electronics | wireless power transmission | deep brain stimulation | antenna O ptogenetics exploits a toolbox of light-sensitive proteins for optical manipulation of neural networks as a powerful means for the study of circuit-level mechanisms that underlie psychiatric diseases (1-4). Canonical optogenetic experiments in the brain require cranial insertion of an optical fiber to illuminate a region of interest (5, 6). Although this approach permits simple behavior modeling, constraints in animal motion and alterations in natural behaviors due to fiber tethering and external fixation complicate use in chronic longitudinal models and in experiments that assess complex responses. Many of these limitations can be bypassed with optoelectronic technologies and wireless receivers, as recently demonstrated in optogenetic stimulation of the brain, the peripheral nerves, and the spinal cord (4, 7-13). Systems that offer soft, compliant mechanical properties and thin, fully implantable designs are particularly advantageous (7). These systems, however, have still not been optimized to fully take advantage of the power of combining mouse genetics/optogentics with long-term beha...

Smart textiles consist of discrete devices fabricated from—or incorporated onto—fibres. Despite the tremendous progress in smart textiles for lighting/display applications, a large scale approach for a smart display system with integrated multifunctional devices in traditional textile platforms has yet to be demonstrated. Here we report the realisation of a fully operational 46-inch smart textile lighting/display system consisting of RGB fibrous LEDs coupled with multifunctional fibre devices that are capable of wireless power transmission, touch sensing, photodetection, environmental/biosignal monitoring, and energy storage. The smart textile display system exhibits full freedom of form factors, including flexibility, bendability, and rollability as a vivid RGB lighting/grey-level-controlled full colour display apparatus with embedded fibre devices that are configured to provide external stimuli detection. Our systematic design and integration strategies are transformational and provide the foundation for realising highly functional smart lighting/display textiles over large area for revolutionary applications on smart homes and internet of things (IoT).

This article focuses on state-of-the-art technologies used in the research on materials, devices and processes to achieve high-performance QD-LEDs.

AbstractsQuantum dot light-emitting diodes (QD-LEDs) are considered as competitive candidate for next-generation displays or lightings. Recent advances in the synthesis of core/shell quantum dots (QDs) and tailoring procedures for achieving their high quantum yield have facilitated the emergence of high-performance QD-LEDs. Meanwhile, the charge-carrier dynamics in QD-LED devices, which constitutes the remaining core research area for further improvement of QD-LEDs, is, however, poorly understood yet. Here, we propose a charge transport model in which the charge-carrier dynamics in QD-LEDs are comprehensively described by computer simulations. The charge-carrier injection is modelled by the carrier-capturing process, while the effect of electric fields at their interfaces is considered. The simulated electro-optical characteristics of QD-LEDs, such as the luminance, current density and external quantum efficiency (EQE) curves with varying voltages, show excellent agreement with experiments. Therefore, our computational method proposed here provides a useful means for designing and optimising high-performance QD-LED devices.