The final lens resembled a rhinestone, with a faceted top and a wide, flat bottom. They installed the lens on a microscope with a camera looking down through the faceted side, and centered tiny objects beneath the flat side.
Each facet captured an image of the objects from a different angle, which can be combined on a computer into a 3D image.
The engineers successfully recorded 3D images of the tip of a ballpoint pen which has a diameter of about 1 millimeter and a mini drill bit with a diameter of 0.2 millimeters.
"Using our lens is basically like putting several microscopes into one microscope," said Li. "For us, the most attractive part of this project is we will be able to see the real shape of micro-samples instead of just a two-dimensional projection."
In the future, Yi would like to develop the technology for manufacturers. He pointed to the medical testing industry, which is working to shrink devices that analyze fluid samples. Cutting tiny reservoirs and channels in plastic requires a clear view, and the depths must be carved with precision.
Computer-controlled machines rather than humans do the carving, and Yi says that the new lens can be placed in front of equipment that is already in use. It can also simplify the design of future machine vision equipment, since multiple lenses or moving cameras would no longer be necessary.
Other devices could use the tiny lens, and he and Li have since produced a grid-shaped array of lenses made to fit an optical sensor. Another dome-shaped lens is actually made of more than 1,000 tiny lenses, similar in appearance to an insect's eye.
|Contact: Allen Yi|
Ohio State University