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Dr Jason Smith

Paul Instrument Fund

University of Oxford

Advanced chemical sensors based on optical microcavity arrays

Chemical sensors are vital tools in healthcare, environmental, and security applications, and there is great advantage to be gained in making them more sensitive, better targeted, more compact, and capable of sensing multiple targets in parallel. Dr Jason Smith is developing an optical sensor that can be used to deliver all of these benefits to the optical sensing of liquids and gases.

“This award has enabled me to build sensors in which the trapping of light in miniature resonators provides enhanced sensitivity. The principle is simple – that light in a resonator bounces back and forth multiple times and so interacts strongly with any microscopic object it encounters. The difficult bit is building good quality resonators and incorporating them into a working device, and it is this that the Paul Instrument Fund grant is allowing me to do.

My aim is to develop the new resonator into a flexible platform for compact and mobile sensing devices. As each resonator is only 1 – 100 cubic micrometres in physical volume it is possible to fit many thousands of them into a single device of a few millimetres in size, allowing multiple sensing operations to be performed in parallel. This could open the door to not just detection but also recognition of different targets such as microbes, chemicals, and aerosols. The sensors are also individually tuneable to aid the targeting and recognition of specific molecules or chemical components.

The Paul Instrument Fund programme was attractive as it highlights the importance of innovative instrument development to the sciences. As a physicist I rely on so many instruments and the opportunity to build a new one was hard to resist!

Prior to the award, I had developed the basic resonators and was able to see that they had attractive properties for sensing applications in a closely controlled lab environment. This award has allowed me to focus effort both on the basic concept and on producing an instrument that can be used by non-experts, an important step if the work is to achieve widespread impact."