Lensless On-Chip Fluorescent Imaging Over an Ultra Wide Field-of-View

We introduce a lensless high-throughput fluorescent detection modality that can simultaneously image micro-objects and labeled cells over an ultra-wide field-of-view (FOV) of ∼8cm² without the use of any lenses, thin-film filters and mechanical scanners. This lensfree platform utilizes total-internal-reflection (TIR) to block the excitation light, and an inexpensive absorption filter to remove the weakly scattered light that does not obey TIR. The emitted fluorescent light from the objects is then detected on the same chip without the use of any lenses. A digital deconvolution algorithm is used to resolve overlapping fluorescent spots, enabling a resolution of ∼40–50 μm over the entire field-of-view. Such an ultra wide field-of-view lensfree fluorescent imaging modality might be very valuable for high-throughput screening applications as well as quantification of rare cells such as circulating tumor cells using ultra-large microfluidic devices.