After years of efforts, MIT researchers have finally created a spectrometer that can be fitted in a device as small as smartphones. According to scientists, the device can be integrated within a smartphone camera and it enables the phone to detect several diseases especially skin diseases and also it can monitor environmental pollutants.
Spectrometer is a device that measures properties of light including intensity, wavelength, frequency, energy, momentum or mass. It is widely used in physical, chemical, and biological research.
Generally a spectrometer is too large to fit inside a smartphone, this also hampers its portability. However, MIT researchers have successfully created a device that is small enough that it can be accommodated by a smartphone camera. For the revolutionary finding, researchers used tiny semiconductor nanoparticles called quantum dots.
Lead author Jie Bao, a former MIT postdoc, explained that Quantum dots are made by combining metals such as lead or cadmium with other elements including sulfur, selenium, or arsenic. By changing the ratio of these metals, researchers were able to create nearly unlimited number of dots which acted as energy bandgap due differences in electronic properties of these dots. Now these energy bands absorb different wavelengths of light similar to a spectrometer.
The spectrometer designed for mobile camera is one-fourth of a one rupee coin in size and contains hundreds of quantum dots and each dot absorbs different wavelengths of light. The quantum dot filters are printed into a thin film and placed on top of a photodetector such as the charge-coupled devices (CCDs) found in cellphone cameras. To analyse the amount of light absorbed, researchers also created an algorithm that works on percentage of photons absorbed.
Although researchers have found success in locating a spectrometer inside a phone but its small size limits its wide range. As bigger the spectrometer, larger will be the number of dots, the more wavelength of light it can cover, greater will be its usability. As of now, researchers used about 200 quantum dots spread over 300 nanometres.
So this is how the next gen smartphones are going to be. These magical devices that have brought the world to your finger tip will now be able to diagnose diseases and environmental pollution, besides it will have many more applications like detecting pulse, etc.
The study appeared in the journal Nature.