Breaking the Mold of Fluorescence Imaging

Microscope with no lenses may be the world’s tiniest.

Fluorescence microscopes are an essential tool in microbiology.

These devices allow scientists to view organic processes at the cellular level by picking up the signals that are emitted when specific fluorescing materials (inserted into tissues by observers) are exposed to the right wavelengths of light. It’s a technique that has been widely used for decades, but it suffers from one critical limitation.

All lensed microscopes are subject to a trade-off: magnification versus field of view. Essentially, in order to zoom in on an object, the overall field of view has to shrink. This inverse relationship means that as lenses shrink, they must either magnify less or capture a smaller overall picture.

Microscope Without a Lens

FlatScope. (Image courtesy of Jeff Fitlow, Rice University.)

FlatScope (Image courtesy of Jeff Fitlow, Rice University.)

A team of engineers from Rice University set out to eliminate this constraint by designing a device capable of capturing 3D microscopic images without a lens, which they call FlatScope.

Thinner than a credit card, this device uses the same type of CCD (charged-coupled device) sensor found in most electronic cameras, but replaces the system of lenses situated in traditional microscopes with a custom amplitude mask.

The mask tightly filters light so that only a small amount eventually reaches the camera sensor itself. That light is converted into data that an algorithm designed by the Rice team uses to develop full images. The magnification is handled by the computer program from there, able to focus on any part of the image field to produce a sharply focused picture.

This process is what qualifies FlatScope as a true microscope.

Possible Uses for FlatScope

In FlatScope, the Rice engineers have developed a physically tiny device that is able to produce highly detailed images on a micro-scale. The potential applications of such a technology are virtually unlimited, but the researchers say the most immediate applications are medical.

FlatScope could, in the future, be used as an implantable endoscope to allow for ongoing observation and analysis of subcellular processes. In particular, implantation of the device in the cranial cavity could allow neurologists to observe brain activity in a way never before possible.

FlatScope’s large field of view and resolution ability could combine to provide a more complete picture of neural processes and their impact on behavior than science has been able to access in the past. Counterintuitively, ditching the lenses in the devices that observe cellular processes might give doctors a clearer perspective than ever.

For more information, check out our video article on Bringing STEM Students Down to the Nanoscale.