Flexible Near-Field Wireless Optoelectronics as Subdermal Implants for Broad Applications in Optogenetics

Abstract

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.

Battery-free, wireless sensors for full-body pressure and temperature mapping

“…Full-body coverage can be accomplished with one or more large-scale loop antennas and external radio frequency (RF) power supplies ( P , typically a few watts; movie S2). The operating range depends on the sizes and numbers of reader antennas, the RF power supplied to them, the sizes of the sensor antennas, and their angular orientation relative to the reader (38). Increasing the tilt angle of the sensor changed the maximum distance over which the signal can be detected only slightly for devices at the edge of the antenna; those at the center and corner regions show decreases in this distance by ~25% for the 60° tilt compared to the 0° tilt cases (fig.…”

Fully implantable, battery-free wireless optoelectronic devices for spinal optogenetics

“…Further improvements in light-dependent modulation of cells or circuits deeper in the spinal cord could be achieved using longer wavelength light in combination with red-shifted opsins [9; 24; 43]. The devices we describe here are capable of powerful illumination of ≥ 50 mW/mm 2 , and can be fitted with red µ-ILEDs [39]. With these options, and with the added use of newer generation opsins with increased light sensitivity [2; 9; 24; 38; 42; 43], activation of even neurons deep in the dorsal horn should be possible.…”

“…The original embodiments involved operation in RF (radio frequency) bands that demand specialized equipment and expertise, limiting their utility for broad application by the neuroscience community, particularly in challenging anatomical regions such as the spinal cord. We recently reported the development of a new platform that leverages wireless near-field communication (NFC) at frequencies (13.56 MHz) commonly found in commoditized consumer and industrial wireless electronic devices [21; 39]. The resulting technology offers numerous improvements over previous approaches, including increased ease of operation and customization of wireless settings to various cage types and environments, with little sensitivity to the presence of objects or physical obstructions, including environments consisting of metals.…”

Thermal Release Transfer Printing for Stretchable Conformal Bioelectronics

“…In this technique, dynamic control of the interfacial adhesion between the stamp and the object to be transferred plays a crucial role in completing successful transfer printing. As shown in Table 1 , several strategies for adhesion control of transfer printing technique have been proposed and applied in the stretchable bioelectronics fabrication (e.g., complex 3D mesostructures,14, 15, 16, 17, 18, 19, 20 wireless biomedical devices,17, 21, 22, 23, 24, 25, 26, 27 and epidermal sensor systems23, 28, 29, 30, 31, 32, 33, 34, 35). …”