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Optical sectioning structured illumination microscopy (OS-SIM) provides optical sectioning capability in wide-field microscopy. The required illumination patterns have traditionally been generated using spatial light modulators (SLM), laser interference patterns, or digital micromirror devices (DMDs) which are too complex to implement in miniscope systems. MicroLEDs have emerged as an alternative light source for patterned illumination due to their extreme brightness capability and small emitter sizes. This paper presents a directly addressable striped microLED microdisplay with 100 rows on a flexible cable (70 cm long) for use as an OS-SIM light source in a benchtop setup. The overall design of the microdisplay is described in detail with luminance-current-voltage characterization. OS-SIM implementation with a benchtop setup shows the optical sectioning capability of the system by imaging within a 500 µm thick fixed brain slice from a transgenic mouse where oligodendrocytes are labeled with a green fluorescent protein (GFP). Results show improved contrast in reconstructed optically sectioned images of 86.92% (OS-SIM) compared with 44.31% (pseudo-widefield). MicroLED based OS-SIM therefore offers a new capability for deep tissue widefield imaging. 

Abstract Micro light emitting diodes (MicroLEDs) provide unrivaled luminance and operating lifetime, which has led to significant activity using devices for display and non‐display applications. The small size and high power density of microLEDs, however, causes increased adverse heating effects that can limit performance. A new generation of electrically insulating high thermal conductivity materials, such as alumina, is proposed to mitigate these thermal effects when used as a substrate as an alternative to glass. This strategy can then be used as a method of passive heat sinking to improve the overall performance of the microLED. In this work, a newly available material, an 80 micron thick alumina ceramic substrate, is shown to yield a 30 % improvement on average in the maximum current drive over a glass substrate. 

Abstract Studies of electrosensory systems have led to insights into a number of general issues in biology. However, investigations of these systems have been limited by the inability to precisely control spatial patterns of electrosensory input. In this paper, an electrode array and a system to selectively stimulate spatially restricted regions of an electroreceptor array are presented. The array has 96 channels consisting of chrome/gold electrodes patterned on a flexible parylene‐C substrate and encapsulated with another parylene‐C layer. The conformability of the electrode array allows for optimal current driving and surface interface conditions. Recordings of neural activity at the first central processing stage in weakly electric mormyrid fish support the potential of this system for high spatial resolution stimulation and mapping of electrosensory systems.