MIT's Nano Flashlight Could Create Cell Phones Able To Detect Viruses

Researchers at MIT have built a new nanoscale flashlight on a chip that they believe could someday result in cell phones that can be used as sensors capable of detecting viruses and other incredibly small objects. The approach used by the researchers to design the nano flashlight on a chip might also be used to create a variety of other micro flashlights with different beam characteristics to create devices for a variety of applications. Scientists say they can make a wide spotlight versus a beam of light focused on a single point depending on the need.

Researchers have endeavored to identify a material by observing how light interacts with the material for decades. Using light to identify a material requires shining a beam of light onto it and then analyzing light after it passes through the material. All materials interact differently with light, allowing the light that passes through the material to provide a fingerprint for that specific material.

Scientists say if they were able to shine multiple wavelengths of light onto a material and capture the interaction of light with it for each color, they could gather a fingerprint that's even more detailed. Currently, a spectrometer is used for this process, but they are relatively large. Reducing the size of the spectrometer would have advantages, such as making the devices portable and enabling additional applications.

Over the years, strides have been made in miniaturizing the sensor for detecting and analyzing the light that has passed through the object. Little had been done for miniaturizing and shaping the flashlight itself. Often the light is provided by a microscale device such as a laser that isn't integrated into the chip as the sensors are. MIT created their device using existing fabrication tech that is currently in use in the microelectronics industry.

Since their device uses common fabrication technologies, they are confident the approach could be deployable at scale with lower cost. The breakthrough could enable industry to create a complete sensor on a chip with both the light source and the detector. The team says their work represents significant advances in the use of silicon photonics to manipulate light waves on microchips for sensor applications.