A Compact Raster Lensless Microscope Based on a Microdisplay

Abstract

Lensless microscopy requires the simplest possible configuration, as it uses only a light source, the sample and an image sensor. The smallest practical microscope is demonstrated here. In contrast to standard lensless microscopy, the object is located near the lighting source. Raster optical microscopy is applied by using a single-pixel detector and a microdisplay. Maximum resolution relies on reduced LED size and the position of the sample respect the microdisplay. Contrarily to other sort of digital lensless holographic microscopes, light backpropagation is not required to reconstruct the images of the sample. In a mm-high microscope, resolutions down to 800 nm have been demonstrated even when measuring with detectors as large as 138 μm × 138 μm, with field of view given by the display size. Dedicated technology would shorten measuring time.

Fluorescence Multi-Detection Device Using a Lensless Matrix Addressable microLED Array

“…In addition, the research presented in this work paves the way for the development of miniaturized microscopes [ 80 , 81 , 82 , 83 , 84 ] based on fluorescence, the gold standard tool used in biology. This promising advancement is envisaged through the utilization of large arrays integrating smaller LEDs, complemented by the appropriate driving circuits.…”

Computational Portable Microscopes for Point-of-Care-Test and Tele-Diagnosis

“…Their costs are approaching an acceptable level due to the industrial mass scale effect. Thus, these cost-effective optical, electronic and computational resources are easy to get [ 124 ]. Obviously, in above mentioned lens-less microscopy setups, smart cellphone microscopes, singlet lens microscopes and super-resolution portable microscopes, the components are easy to be collected by a designer.…”

“…These available hardware and software environments provide the base condition for developing computational, portable and low-cost microscopes. Briefly, this is the best era for POCT and tele-diagnosis [ 124 , 125 , 126 , 127 ]. It is believable that more ideas and innovations for developing computational, portable and low-cost microscopes for POCT and tele-diagnosis would boom.…”

24‐1: Can Light Microscopes Really Be Chip‐Sized?

“…In conventional DHM microscopes the sample is placed near the camera to have the maximum field-of-view and resolution. However, in the raster lensless microscope the sample is positioned near the micro-display to obtain the maximum resolution from the LED pitch [6,7]. As it is schematically shown in Figure 3, as each LED is lit, the intensity of the light transmitted through the sample is captured by a camera, and a scan with all the LEDs in the array is performed.…”

“…The resolution will improve if smaller size and pitch are used. For example, in [7] smaller LED sizes are obtained with optical demagnification and the resolution of the raster microscope is reduced accordingly. However, only small arrays of LEDs have been achieved with nanometre LED sizes [10].…”