Lensfree microscopy on a cellphone

TLDR

A lensfree holographic microscope on a cellphone eliminates bulky optics, offering a lightweight, cost‑effective tool for telemedicine to address global health challenges. The study demonstrates lensfree digital microscopy on a cellphone. The 38‑gram device attaches to the phone camera, uses a simple LED for vertical illumination, and records incoherent LED‑scattered light to form holograms that are digitally reconstructed into microscopic images. The microscope successfully imaged micro‑particles, blood cells, and Giardia lamblia, demonstrating its performance.

Abstract

We demonstrate lensfree digital microscopy on a cellphone. This compact and light-weight holographic microscope installed on a cellphone does not utilize any lenses, lasers or other bulky optical components and it may offer a cost-effective tool for telemedicine applications to address various global health challenges. Weighing ∼38 grams (<1.4 ounces), this lensfree imaging platform can be mechanically attached to the camera unit of a cellphone where the samples are loaded from the side, and are vertically illuminated by a simple light-emitting diode (LED). This incoherent LED light is then scattered from each micro-object to coherently interfere with the background light, creating the lensfree hologram of each object on the detector array of the cellphone. These holographic signatures captured by the cellphone permit reconstruction of microscopic images of the objects through rapid digital processing. We report the performance of this lensfree cellphone microscope by imaging various sized micro-particles, as well as red blood cells, white blood cells, platelets and a waterborne parasite (Giardia lamblia).