Based on technology invented at the University of Cambridge, our micromechanical sensor can detect material down to the femtogram level – a trillionth of a gram.

The sensor works by detecting very small changes in mass attaching themselves to the sensing surface. We have also developed a way to place a layer of material on the sensor – the functionalisation layer – that allows us to be highly selective about the material we measure.

The sensor works by having high resonant frequencies in the 2-3GHz range. Any small change in the resonant frequency relates directly to an amount of mass accumulating on the sensor. What sets us apart is our proprietary method for generating two resonances in the same device. This allows us to detect simultaneous variations of mass and temperature using the same sensor – meaning the sensor can be self-referencing to ensure accuracy across a range of temperatures.

Our sensor is based on film bulk acoustic resonator (FBAR) technology. It is tiny – as thin as a human hair and just 0.7mm on a side – so we can get 60,000 sensors on an eight-inch wafer. The sensors consume very little power – in the microwatts range – and can withstand very high temperatures of more than 500°C.

The advantages of our sensor include high sensitivity and fast response times, without the need for complicated cooling systems. As it is a semiconductor device, it can also be fully integrated with CMOS circuitry to provide a single tiny chip that can sense and do all the processing in one chip.