Physicists have created a pressure sensor that can weigh a feather. The device can be used in medicine – for example, to measure heart rate and to monitor breathing and movements. This is stated in the work of scientists from the University of Sussex, a description of which is published in the journal Advanced Functional Materials.
Pressure sensors are capable of measuring various deformations resulting from the force applied to them: for example, surface irregularities, acceleration, and other phenomena. They are based on an elastic substrate on which an electric circuit is created – when the substrate is stretched, its resistance changes, which allows us to measure the above phenomena.
However, pressure sensors have significant limitations: as a rule, they are able to work in a very narrow mass range and measure only a small amount of forces.
In a new work, researchers partially solved this problem. They created a sensor based on a composite polymer material that can stretch almost twice. As it stretches, its resistance changes very smoothly, but at the same time significantly – almost 10 million times in comparison with the initial state.
The resulting sensor is able to respond to changes in pressure of 0.1% and withstand stretching by an additional 80% of its length compared to existing analogues. This makes it possible to use them both for determining the mass of a conventional fluff and for more serious measurements.
“Developers of modern foil-based pressure sensors usually prefer the accuracy and reliability of measurements to the detriment of sensitivity and the range of measured values. Nanocomposite materials are devoid of these drawbacks, but their implementation is hindered by nonlinear effects, due to which the measurements can be unpredictable. Our sensors have no such problem”Sean Ogilvy, lead author of the research
Previously, scientists from the University of Tokyo successfully shot a video of single molecules in motion at a speed of 1600 frames per second. This is 100 times faster than previous experiments of this kind have shown.