Researchers at Penn State have developed a new method of imaging that does not require a lens but uses reconfigurable particle-based masks instead to take multiple shots of an object. The lensless camera uses electric-field directed self-assembling mask technology that is ideal for use in lower-cost and faster disease diagnosis. It could also find use in the enhancement of optical microscopy and could enable thinner cellphone technology.
The lensless camera is based on a mask of microscopic gold wires placed near the object that will be imaged. The mask scatters the light reflected off the object and an image sensor collects the light. An electric current rearranges the particles in the mask, producing a new mask with every iteration, and the system records each new image. The multiple light captures are then computationally reconstructed into the original object image, resulting in highly improved resolution and quality.
"We are not the only group to do lens-free imaging," explained Jennifer Miller, a doctoral candidate in chemistry and a first author on a paper recently published online in ACS Nano. "What is different about our work is that typically you would need to make multiple masks and physically move them around to get multiple images. This becomes bulky and expensive and negates some of the simplicity that is the advantage of lens-free imaging."
In typical microscopy, there exists a trade-off between the field of view and the power of the resolution, so a 10x field is wider than a100x field. By using a lens-free imaging technology, it is possible to combine a wide field of view with high magnification for lower-cost images and faster diagnosis of disease. This could be especially useful in developing countries where high-end microscopes are not available.
"Traditional masks are passive," said co-first author Cheng-Yu Wang, doctoral candidate in electrical engineering. "We can add functionalization to our microwire, like polarization, selectivity and plasmonic effects, that make our imaging system