Researchers have developed graphene-based sensing technology using G-Putty material — a highly malleable graphene blended putty. The printed sensors are 50 times more sensitive than the industry standard and outperform other comparable nano-enabled sensors in an important metric: flexibility. Maximizing sensitivity and flexibility without reducing performance makes the technology an ideal candidate for the emerging areas of wearable electronics and medical diagnostic devices.

The team demonstrated that it can produce a low-cost, printed, graphene nanocomposite strain sensor. Creating and testing inks of different viscosities (runniness), the team found it could tailor G-Putty inks according to printing technology and application. In medical settings, strain sensors are a valuable diagnostic tool used to measure changes in mechanical strain, such as pulse rate, or changes in a stroke victim’s ability to swallow. A strain sensor works by detecting this mechanical change and converting it into a proportional electrical signal, thereby acting as mechanical-electrical converter. While strain sensors are currently available, they are mostly made from metal foil that poses limitations in terms of wearability, versatility, and sensitivity.

The team turned G-putty into an ink blend that has excellent mechanical and electrical properties. The inks can be turned into a working device using industrial printing methods, from screen printing to aerosol and mechanical deposition. An additional benefit is that the team can control a variety of different parameters during the manufacturing process, which provides the ability to tune the sensitivity of the material for specific applications calling for detection of minute strains.

The development of the sensors represents a considerable step forward in wearable diagnostic devices — devices that can be printed in custom patterns and comfortably mounted to a patient’s skin to monitor a range of different biological processes. The team is exploring applications to monitor real-time breathing and pulse, joint motion and gait, and early labor in pregnancy. Because the sensors combine high sensitivity, stability, and a large sensing range with the ability to print bespoke patterns onto flexible, wearable substrates, the team can tailor the sensor to the application.

For more information, contact Thomas Deane at This email address is being protected from spambots. You need JavaScript enabled to view it.; +353 1 896 4685.

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Composites Consumer electronics Detectors Electronic equipment Force Sensors and Resistors Materials Materials properties Medical equipment and supplies Medical, health and wellness Medical, health, and wellness Nanotechnology Sensors Sensors and actuators Wearables

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    00:00:00 [Music] this project was about using graphine as an additive in a polymer to give a composite material with with useful sensing properties the composit that we use are actually quite unusual and the reason for this is that the polymer that we use was one that is not normally used in composits it was a very soft deformable polymer that is actually very

    00:00:28 familiar to most kids my my own kids play with it at home it's basically Silly Putty so what we did was we put graphine into this polymer and we found we got a composite with very very unusual uh physical properties electrically the composite became conductive but mechanically it was still this squashy squidgy material so graphine is an atomically thin sheet of

    00:00:51 carbon now that might sound exotic but we've all mesh related the related material graphite I mean it's the lead and pencils and graphite is material that's made of carbon but it's a bit like a deck of cards it's a bunch of one atom thin sheets of carbon stacked on top of each other very very quickly we realized that when you took the composite the silly putty with graphine

    00:01:14 in it and you squashed it or deformed it in any way its electrical resistance would change dramatically so that was that was really interesting because we knew from previous work that That's the basis of an electromechanical sensor the basis of a sensor which can measure formation by giving an electrical readout so we found that when the the sensor is held up here to the cored

    00:01:36 artery that that pulsing of that artery can actually be be detected and can be read out in an electrical resistance change so we can measure the pulse which gives a measure of the heart rate but the sensor is sensitive enough that we can also get the blood pressure out of that and that's actually quite important we can measure blood pressure of course we can but it's not straightforward to

    00:01:58 measure it continuously and that's what this sensor can do so we believe that there will be a lot of applications in medical devices and for example in Diagnostics our sensors had sensitivity factors of up to 500 so already we were hundreds of times better than a typical strain sensor and we had Ed what is essentially a children's toy and we'd added a very very small amount of

    00:02:20 graphine and so it really shows the power of nanom materials a small amount of Nano can really turn the ordinary into something extraordinary [Music] [Applause] [Music] oh