Sensors for the real world
21 Dec 2012 by Evoluted New Media
New resonators for gravimetric sensing developed at the University of Cambridge negate the effect of temperature so that they may be used in numerous industries.
Over the last decade there has been an increased interest in developing these sensors but their response to variation in temperature has thus far prevented them from being used outside the laboratory.
Now, researchers from the Department of Engineering have designed a thin film bulk acoustic wave resonator that allows simultaneous measurement of temperature and mass loading in a single device. The device has been designed to have two resonances which react differently to mass and temperature changes.
“This has two consequences,” explained Dr Luis Garcia-Gancedo, a member of the Dr Andrew Flewitt’s group at the Department of Engineering who contributed to the research. “First, we are able to eliminate the effects of temperature completely regardless of its non-linearity. Secondly, we are able to measure mass and temperature with extremely high sensitivity at exactly the same location, which we haven’t been able to do before.”
The resonator can detect masses to the order of 10-15 grams, approximately the size of one virus. The small size of the resonator (typically a few micrometres square) means they can be embedded easily into multiple devices.
The group has teamed up with Cambridge Enterprise and is looking at two primary applications for the resonators: biological systems and physical sensing. For biological systems, the resonators could be used in applications such as detecting viruses, or contaminants in drinking water. Physical sensing applications include air quality and pressure monitoring.
“One of the problems with existing sensing technology is that if you’re trying to measure two different physical properties, the sensors are often based on two different mechanisms. The integration of two different sensing mechanism means that you often end up with a bulky item. But what we have developed uses exactly the same technology with exactly the same electronics, without any increased in size,” said Garcia-Gancedo.
