With 3D printers all but widely-known now, it only remains to have an accurate and portable 3D scanner to practically produce anything on-the-go. The current 3D scanners are all bulky and very expensive but we may soon have that functionality installed in our smartphones.
A team of CalTech researchers led by Ali Hajimiri has designed a small camera chip that can enable a smartphone to do an accurate 3D scan of an object.
The tiny silicon chip called nanophotonic coherent imager (NCI) only measures one millimeter square and can conveniently be placed within smartphones. It uses a type of Light Detection and Ranging (LIDAR) technology in capturing an item’s width, depth and height. Basically, a laser is shined on the object so the light waves that bounce off of it can serve as guide for the imager when capturing the measurement data.
The technology used on the chip is further explained by Caltech:
“Such high-res images and data provided by the NCI are made possible because of an optical concept known as ‘coherence’. If two light waves are coherent, the waves have the same frequency, and the peaks and troughs of light waves are exactly aligned with one another. In the NCI, the object is illuminated with this coherent light. The light that is reflected off of the object is then picked up by on-chip detectors, called grating couplers, that serve as ‘pixels’, as the light detected from each coupler represents one pixel on the 3-D image.”
According to Dyman & Associates Risk Management Projects, LIDAR technology is commonly used in self-driving cars, robots and precision missile systems due to its effectiveness in identifying locations and objects. Although the concept of LIDAR is not that new, their idea of having “an array of tiny LIDARs on our coherent imager can simultaneously image different parts of an object without the need for any mechanical movement” is a novel one.
Basically, every pixel on the sensor can separately assess the intensity, frequency and phase of the reflected waves, thereby creating a piece of 3D information. The combination of all those pieces of 3D data from all the pixels results in the full 3D scan.
Caltech’s concept allows for the development of a tiny and relatively cheap scanner without sacrificing the accuracy. Dyman & Associates Risk Management Projects reported that the new chip can create scans that closely resemble the original within microns.
At present, the prototype Caltech has made only has 16 pixels on it, just enough to scan small objects such as coins, but they are reportedly working on scaling it up to thousands of pixels.