An ultra-low-cost focus-tunable smartphone-based microscope

Abstract

By taking advantage of the inherent flexibility of low-cost 3D printing materials, we achieved an optical focus tuning accuracy of ~5 micron with a novel structure design. It shrinks the mechanical displacement by a factor of ~11 through a seesaw-like component. Combing with the built-in flashlight illumination and an off-the-shelf smartphone lens, the total manufacturing cost of our smartphone-based microscope is less than 4 USD. We demonstrated the capability of this design in imaging thick biological specimens. We further applied this device in the cell culture monitoring of VX2 tumor cells because of its portability and flexibility.