School of Engineering Department of Mechanical and Aerospace Engineering 158 Development of Low-cost Smartphone-based Microscope for Global Health Supervisor: LEE Yi-Kuen / MAE Student: LEUNG Chi San Ivor / PHYS Course: UROP2100, Fall UROP3100, Spring UROP1000, Summer A new prototype of a low-cost fluorescence microscope is constructed. The prototype comprises a creditcard-size Raspberry Pi computer integrated with a high-quality camera module, commercial microscope objective lenses, long-pass filters, dichroic mirrors, and other components such as 3D-printed parts. Its performance is evaluated and compared with a commercial microscope, Olympus IX 70, in the following aspects: image quality (in both bright-field and fluorescence mode) and point spread function. In addition, the z-axis positioning accuracy and the signal-to-noise ratio of the prototype are measured. Assessment results show that the prototype, with a cost as low as USD $220, performs comparably to the commercial microscope valued at USD $28000, demonstrates high accuracy in z-axis positioning and possesses a high signal-to-noise ratio.