Microlens Enhanced Mobile Microscopy*

A mobile microscope is a portable device that uses a smartphone camera for microscopic imaging. Their accessibility makes them invaluable for applications in resource-limited settings where traditional equipment is unavailable. However, typical smartphone microscopes are often constrained by limited resolution. To enhance resolution, we integrated a microlens array composed of 150μm glass microspheres. When placed close to the sample, the microlens increase magnification by up to ~3x by generating virtual images. The transition between real and virtual image formation was analyzed using finite-difference time-domain simulations. This improved setup enabled high-resolution imaging in both bright-field and fluorescence modalities. For fluorescence imaging, a 450nm diode laser illuminated the sample at ~90 degrees relative to the camera, and an emission filter blocked the unwanted light. Bright-field imaging was achieved using an LED. To validate the system’s capability, we imaged sickle cells, which are deformed red blood cells, clearly capturing their characteristic shape. Our approach transforms a low-cost mobile microscope into a high-resolution imaging tool, demonstrating its potential for advanced microscopy applications in resource-limited environments.