High-speed imaging provides an opportunity to access detailed information in various biomedical fields. However, conventional high-speed cameras still suffer from slow framerates or difficulty to resolve dense information. This study presents a compact ultrafast camera by combining a compound eye camera inspired by the nature insect with an offset array. OFAC is packaged within 10.4 × 8.3 × 1.5 mm3 excluding image sensor boards, and successfully resolves high-temporal image sequences up to 91,200 framerate. The proposed ultrafast compound eye camera will provide new methods to approach miniaturized high-speed biomedical imaging.

Focused light field cameras utilize microlens arrays (MLAs) as an imaging system to obtain spatial and angular information. MLAs are efficiently fabricated by thermal reflow whereas MLAs formed by thermal reflow have relatively small f-numbers, resulting in small depth-of-field. Here we report a focused light field camera with large f-number by incorporation solid immersion MLAs. Solid immersion using PDMS spin coating over conventional MLAs facilitates large-area fabrication of large f-number MLAs using refractive index differences. Solid immersion MLAs extend depth-of-field several times. This method can broaden focused light field camera application range.

The Tabanidae has a unique eye structure that structural color filter in cornea display advantages for color vision system. The combination of color filter layers and ommatidia can provide the advantages of miniaturization, and multispectral imaging. We report an ultrathin multi-spectral camera inspired by the structure of Tabanidae vision system. The ultrathin multi-spectral camera consists of Fabry-Perot color filter arrays, microlens arrays with chrome aperture, and a CMOS image sensor. The fully packaged camera shows a FWHM under 31nm, a total track length of 1mm. This provides new opportunity for point-of-care testing (POCT) and medical applications.

We demonstrate a near-infrared (900-1650nm) spectral sensor based on an array of 16 pixels for classifying and quantifying materials and their composition. These pixels consist of resonant-cavity enhanced photodetectors containing a thin absorbing layer, tuning element and cavity. Using a wafer-scale optical lithography process, we achieve a tunable, wavelength-specific response with narrow linewidths of 50nm and high responsivity (R>0.1A/W). The customizability of the response, small-size and robustness make it suitable for portable spectroscopic solutions in a wide variety of applications. The sensing performance is demonstrated on the prediction of moisture in rice with a coefficient of determination of R^2=0.95.

Handheld spectrometers have been reduced in size due to advanced microfabrication processes, but have significantly poor spectral resolution compared to conventional spectrometers. Here we report compact and ultrathin spectrometer that improves optical performances in visible region. Designed spectrometer improves low spectral resolution and high optical sensitivity through the back-reflection grating structure. Spectrometer is fabricated with the ultrathin structure with the overall thickness of 6 mm. With these simple internal optical elements, this compact and ultrathin spectrometer can be utilized in non-invasive biomonitoring sensor.

This paper reports a miniaturized spectrometer with enhanced spectral resolution using electrothermal MEMS grating. The MEMS (Micro-electromechanical systems) grating is fabricated on SOI (Silicon on Insulator) wafer and consists of Aluminum/Silicon bimorph, reflective diffraction grating, entrance and exit slit. The MEMS grating scans and single pixel photodiode detects the diffracted spectral signal. The electrothermal actuation and higly dispersive optics of the MEMS grating provides large stroke with low operation voltage to widen the spectral range, and facilitates enhaced spectral resolution in small volume, respectively. This miniaturized spectrometer will deliver diverse application in various fields by providing accurate on-filed molecular analysis.

Quartz-enhanced photoacoustic spectroscopy (QEPAS) is one of the most efficient ways to obtain sensitive, selective, robust gas sensors, where the signal can be given with a fast response and measured continuously. The main drawback of QEPAS comes from using a quartz tuning fork (QTF) as a mechanical transducer. QTF is not designed for photoacoustic gas sensing, and its further integration is limited. We propose a silicon resonant MEMS based on a capacitive transduction mechanism with a limit of detection comparable to that of a QTF. This sensor is potentially an efficient sound wave transducer that can advantageously replace a QTF