These pressure-sensitive “e-stickers” are just as functional as regular silicon circuits, but now, they can be fabricated into fun, flexible shapes, such as butterflies or monkeys. The research team from the KAUST Computer, Electrical, and Mathematical Science and Engineering Division, led by scientist Muhammad Hussain, just published their study in the Advanced Material Technologies journal.
In order to handle monitoring applications, like digitizing analog signals, the flexible printed circuits need regular silicon components. The goal of this project is to create a non-invasive health monitor, but the researchers explained that rigid modules, like the silicon components, can increase the device weight and create hot spots on your body, defeating the purpose.
Hussain explained, “We are trying to integrate all device components-sensors, data management electronics, battery, antenna-into a completely compliant system. However, packaging these discrete modules on to soft substrates is difficult.”
Looking for a way to achieve their goal and find potential electronic skin applications, the team created a sensor, with narrow strips of aluminum foil inside, that will change electrical conductivity depending on how it is bent. Their technique, which involves printing conductive ink onto polymer and cellulose materials, allows for the devices to be produced with high speed and at low cost.
The team 3D printed the decal electronics using techniques that encased both the foil and silicon chips into a polymer film, backed by a layer of adhesive. High-mobility zinc oxide nanotransistors on silicon wafers enable maximum flexibility.
Doctors could use this device to monitor a patient’s activity levels or breathing patterns without having to attach a bulky, invasive object to the skin. But the team wanted to investigate if there was a way to make the e-sticker sensors work in other applications as well, so they used inkjet printing to write conductive wiring patterns onto a variety of surfaces, like clothing or paper, and the decals were then attached to different locations.
Galo Torres Sevilla, a KAUST Ph.D. graduate and the first author on the study, said, “You can place a pressure-sensing decal on a tire to monitor it while driving and then peel it off and place it on your mattress to learn your sleeping patterns.”
Hussain said, “I believe that electronics have to be democratized – simple to learn and easy to implement. Electronic decals are a right step in that direction.”
Discuss in the 3D Printed Health Monitor forum at 3DPB.com.
[Sources: Futurism / newelectronics]