Year/Course: 2020-2021, Lent 2021

Inventor: Dr. Tom Albrow-Owen, Centre for Advanced Photonics and Electronics, Engineering
More details: Nanowires replace Newton’s famous glass prism
Mentor: Marc Bax

Spectrometry is a key workhorse in all scientific disciplines, using light to probe matter and identify its constituent molecules or observe chemical processes. It is widely used in areas such as the pharmaceutical industry, food production, crop monitoring and soil analysis, as well as applied and fundamental research. Traditional spectrometers are large laboratory-based systems with complex optics; while these designs can be miniaturised, scaling down further than the centimetre scale is extremely challenging.

The research team has built a prototype of a tiny spectrometer sensor made from an individual semiconductor nanowire – around one thousand times smaller than any previous system – which can analyse the whole visible light spectrum. The nanowires can be manufactured in a way that allows control over which light frequencies can be detected, so it would also be possible to build a device that could detect non-visible light wavelengths such as ultraviolet and infrared.

Having such a tiny sensor opens up a whole new set of possibilities in miniaturised or in-situ applications, but also for spectral imaging. For example, you could create an array of thousands of sensors, one for each pixel in a camera, allowing spectral signatures to be superimposed on a visual photograph. A succession of such images would create a spectroscopic video, which could allow cellular and chemical processes to be observed and recorded over time.

However, highly-specialised, novel processes would need to be developed to produce these sensors in a scalable fashion, which means that any commercial venture would need significant up-front investment into new manufacturing techniques.

The challenge for the i-Team is to justify such an effort by identifying and investigating applications where it would be useful to have a miniature spectrometer sensor or spectral imaging array. For example, what could you do if you included a spectrometer in a mobile phone? What could you do with a large array of spectrometers that can observe a whole area over time? What are the applications that need an ultra-miniature sensor and where existing systems are not yet small enough? And, in the short term, what do the inventors need to do to take their invention to the next stage?