It is the size of a grain of salt, but still an incredibly powerful camera . Developed by a team of researchers from Princeton University and the University of Washington, it is capable of capturing sharp, full-color images like cameras up to 500,000 times larger than this.
The ultra-compact optical device could allow super-small robots to detect their surroundings, or even help doctors see if there are any problems within the human body.
Evolution of the camera
Researchers have managed to avoid the Achilles heel of micro-sized cameras from delivering distorted or blurry and poor-quality images thanks to a new approach. Normal cameras use a series of curved glass or plastic in their lenses to focus light when taking pictures. The new microcamera has a new optical system with a technology called metasurface that works in the same way and can be produced like a computer chip. The material is lined with 1.6 million cylindrical posts , each the size of a human immunodeficiency virus (HIV) particle. Each cylinder works as an optical antenna and has a very specific design aimed at adequately capturing the light reflected by an object. Signal processing algorithms then produce a full color image from that data.
Very sharp images
The photos taken by the small device offer the highest quality images with the widest field of view of any full-color metasurface camera developed to date.
Thus, the high definition camera is only half a millimeter wide but the resulting images are much sharper than other small sensors. In tests, the researchers showed that the new sensor captured 720 x 720 pixel images in full color , capturing wavelengths between 400 and 700 nm in natural light, with a spatial resolution of 214 line pairs per mm. It has a 40-degree field of view and an f-number of 2 (f / 2), and experts say the shots are on par with those captured by a conventional composite camera lens that is half a million times larger than your new sensor.
According to the researchers, the camera can also perform well in natural light, rather than the pure laser light or other highly idealized conditions required by previous metasurface cameras to produce good quality images.
“It has been a challenge to design and configure these little microstructures to do what you want. For this specific task of capturing wide-field-of-view RGB images, it was previously unclear how to co-engineer the millions of nanostructures together with post-processing algorithms, ”explains Ethan Tseng, a Princeton student who co-led the study.
The possibilities are endless with these micro cameras. And this new micro-optical system could be used for many interesting purposes. The next thing is to improve the image and see how to add object detection functions and other features that would make this instrument a revolution for medicine and robotics.
Referencia: Tseng, E., Colburn, S., Whitehead, J. et al. Neural nano-optics for high-quality thin lens imaging. Nature Communications 12, 6493 (2021). DOI: https://doi.org/10.1038/s41467-021-26443-0
