Scientists from The Pennsylvania State University (Penn State) are developing a new type of imaging system that does not necessitate the use of a lens but instead uses configurable particle-based masks to capture multiple images of an object.
The self-assembling mask technology, directed by an electric field, is anticipated to have applications in lower-cost and faster disease diagnosis, the improvement of optical microscopy, and may even pave the way to thinner cellphone technology.
How it Works
The team developed a mask of microscopic gold wires and positioned it near the object to be imaged. The mask distributes the light reflected off the object and an image sensor gathers the light. An electric current reorganizes the particles in the mask, creating a new mask with each iteration, and the system captures each new image.
The various light captures are subsequently rebuilt into the original object image using computer technology, leading to highly enhanced quality and resolution.
We are not the only group to do lens-free imaging. 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.
Jennifer Miller, Study First Author and Doctoral Candidate in Chemistry, The Pennsylvania State University
In standard microscopy, there is a compromise between the power of the resolution and the field of view; hence a 10x field is broader than a100x field. With the help of lens-free imaging technology, a broad field of view can be combined with high magnification for faster diagnosis of disease and lower-cost images. This could be particularly handy in developing nations, where leading brands of microscopes are not available.
Traditional masks are passive. We can add functionalization to our microwire, like polarization, selectivity and plasmonic effects, that make our imaging system more powerful.
Cheng-Yu Wang, Study Co-First Author and Doctoral Candidate in Electrical Engineering, The Pennsylvania State University
With regard to cellphones, one key contributor to their bulk is the camera lens that needs to be at a specific distance to the detector. A lens-free camera could help reduce the requirement for space. Similarly, a lens-free system integrated to a cellphone could change the cellphone into a low-power microscope.
Besides Miller and Yang, senior authors on the study titled, “Particle-based reconfigurable scattering masks for lensless imaging,” are Christine Keating, distinguished professor of chemistry, and Zhiwen Liu, professor of electrical engineering. The paper has been published in the ACS Nano journal.
The research was funded by the Penn State MRSEC, Center for Nanoscale Science, and the National Science Foundation. A patent application has been filed by Penn State for this technology.
Miller, J. R, et al. (2020) Particle-based reconfigurable scattering masks for lensless imaging. ACS Nano. doi.org/10.1021/acsnano.0c04490.