Humans are quite good at assessing the properties of things just by looking at them, but we have discovered that we can do much much better with technology. Optical spectrometers study the absorption and emission of light, and are used in many different fields to analyze and identify the characteristics of a structure. Using optical spectrometers, we have been able to work out the molecular components of objects, from what molecules themselves are made of to the composition of distant nebulae.
Researchers have now developed an ultra-compact spectrometer made of a single nanowire. This is an impressive breakthrough as scientists have been struggling to miniaturize these systems. Due to the physical constraints on the distances that light must travel in these systems, they are usually bulky, making it almost impossible to shrink them down to anything smaller than a coin. So researchers have had to get creative.
As reported in Science, researchers led by a team from Cambridge University developed an approach that uses a nanowire 1,000 times thinner than a single human hair to capture light, and clever computational software that can reconstruct the full spectrum of light signals. The device is constructed from already commercially available nanowires, and it is so small that it could be integrated easily into a smartphone.
“A spectrometer is very different from a standard camera because it can actually capture much more than what we can see or what [the camera] can see. And that means that for many situations in our daily life a spectrometer could really give us a lot of beneficial information,” senior author Dr Tawfique Hasan, from the Cambridge Graphene Centre, told IFLScience.
The applications both academic, industrial, and personal are exciting. It could be used in drones to monitor the environment and detect pollutants, or assess the quality of pharmaceutical products. It can also identify a wide range of counterfeit goods. By extending the observations capabilities from visible light to infrared, it could be used to estimate the ripeness of a fruit. Want to know how much sugar the apple you’re holding has? Point your tiny spectrometer and get an answer.
“One of the most important aspects that our paper conveys is that it is not only a spectrometer that we have demonstrated, we are demonstrating a platform,” Dr Hasan said. “If you have access to light-sensitive materials that have different bandgaps across certain wavelength regions, you could essentially use the same concept, the same platform, and create a new spectrometer.”
The team really stress the versatility of this approach. By changing either the hardware or the software others could come up with their own ultra-miniaturized spectroscopy systems, and their applications are endless.