Professor Aydogan Ozcan at UCLA has used 3D printing to create a microscope which can be attached to a smart phone. The product enables smartphone cameras to "see" particles some 90 nanometers across.
So how small is that? Consider that a single virus clocks in at something like one thousandth the width of a human hair.
Ozcan and Company call their invention "the first cellphone-based imaging system" which can detect single nanoparticles and even viruses.
The UCLA device utilizes a laser diode to illuminate objects at a steep angle of about 75 degrees which prevents the lens from picking up scattered light and provides imaging without significant signal-to-noise ratio which would impede the process.
Ozcan says scientists used the device to detect a single particle of the human cytomegalovirus, a virus often blamed for birth defects, and that those particles were between 150 and 300 nanometers in size. He added that the device has detected "marked" nanoparticles in the 90-100 nanometer range, and that his team's results were verified using an electron microscope.
At under a half a pound, Ozcan thinks the device can be cheaply manufactured and useful for conducting biomedical tests in remote areas where the size of the device would be critical.
The team, working on electrical engineering and bioengineering at the UCLA Henry Samueli School of Engineering and Applied Science, aimed to create a device which could replace bulky – and often delicate and expensive – microscopes and lab equipment.
"This imaging platform could be used for specific and sensitive detection of sub-wavelength objects, including bacteria and viruses and therefore could enable the practice of nanotechnology and biomedical testing in field settings and even in remote and resource-limited environments," Ozcan says. "The results also constitute the first time that single nanoparticles and viruses have been detected using a cellphone-based, field-portable imaging system."
Ozcan says the fluorescent microscope device was fabricated by a 3D printer which depends on a color filter, an external lens and a laser diode to do its work. The diode shines on fluid or solid samples at an angle of roughly 75 degrees, and it's that sharply oblique illumination which cancels out scattered light which would interfere with the intended image.
Ozcan holds 22 patents and has some 15 pending patent applications for his inventions in nanoscopy, wide-field imaging, lensless imaging, nonlinear optics, fiber optics, and optical coherence tomography. He's also the author of one book, and co-author of more than 300 peer reviewed research articles in major scientific journals.
The device is attached to the camera module on a smartphone.
Qingshan Wei, Hangfei Qi, Ting-Ting Wu, Wei Luo, Derek Tseng, Zhe Wan and Zoltan Gorocs, So Jung Ki, Laurent Bentolila and Ren Sun were also critical to the development of the microscope, which was funded by Presidential Early Career Award for Scientists and Engineers, the Army Research Office, Nokia University Research Funding, the National Science Foundation, the National Institutes of Health, and the Office of Naval Research.