February 17, 2017
‘Eagle Eye’ system might allow for hi-def sand grain-sized cameras
A team of engineers has created a camera that could give eagle-eye vision to both tiny drones and surgical probes, according to a new paper in the journal Science Advances.
Previously, the same team had used a process known as femtosecond laser writing to 3D-print tiny lenses right onto an image-sensing chip. To produce super-sharp images, the scientists used this same method to make clusters of four lenses at a time. The lenses vary from wide to narrow and low to high resolution, and pictures can then be mixed into a bull's-eye shape with a sharp image in the middle, which is comparable to how eagles see.“If you take a snapshot with your smartphone, and you want to magnify it, you cannot see the details anymore because they are pixelated,” team member Harald Giessen, a physicist at the University of Stuttgart in Germany, said according to PBS. “Using our sensor, you can zoom into the image without losing anything, because of the higher density of pixels.”
Tiny 3D Printed Lenses
The four lenses may be packed into an area no bigger than 300 micrometers by 300 micrometers, a size comparable to a single grain of sand. The scientists said the dimensions of the entire camera setup could get smaller with design adjustments to load up or combine lenses, or as more compact chips become obtainable.
In the wild, animals must balance their visual necessities and their brain power. Humans and many other vertebrates resolve this issue with what is known as "foveated" vision, with the sharpest image in the center and a wide range of lower-clarity vision at the edges.
The study tam said their step will be to 3D-print a lens array on the tiniest available image sensors, measuring approximately .04 square inches, or 1 square millimeter, with the lenses spanning more of the top of the sensor.
“A key challenge, as recognized by the authors, is the fabrication time and cost, making mass production difficult at the moment,” noted Yizheng Zhu, a physicist at Virginia Tech who wasn’t involved in the study. “Hopefully, as technology advances, more improvements can be made in this area.”
Image credit: Simon Thiele