Graphene Improves Flexible and Wearable Electronics

At 200 times stronger than steel, graphene has been hailed as a super material of the future since its discovery in 2004. The ultrathin carbon material is an incredibly strong electrical and thermal conductor. Here, researchers demonstrate that graphene can greatly improve electrical circuits required for wearable and flexible electronics.

"Flexible and wearable electronics can be made of soft materials like polymers that can't sustain high temperatures," says Chen-Hsuan (Steve) Lu (MS '20)  , a Caltech graduate student and lead author of the three studies. "Our method allows us to grow graphene directly on the substrates at a low temperature, preventing any damage to sensitive materials."

Transcript

00:00:00 [Music] we have developed a unique method to grow graphene and this method is scalable industrially compatible and it can be used for flexible substrates and or biomedical applications graphing is like one Atomic sheet of carbon forming honeycomb structure each Atomic layer is strong and they have

00:00:30 excellent electrical conductivity and also excellent thermal conductivity most people try to fabricate graphene using a very high temperature method but a lot of these flexible substrates that we need to use to make flexible electronics for instance they consist of polymers you cannot treat them at high temperature otherwise they're immediately break and so we developed

00:00:55 the graphene growth process at room temperature our process is called plasma enhanced chemical vapor deposition process pecvd a unique method for graphene growths on different substrates that could be useful for many applications plural graphing we only use the sheeting from the plasma itself we need the reacting gas we use methane and hydrogen

00:01:20 medicine provides a carbon source and the plasma helps dissociate methane into reactive species and those species can react on top of the metal surface on the substrate which forms graphing on top we have grown graphene on very thin metal wires on top of polymers and then we want to demonstrate whether the electrical circuits made out of these metal wires can survive many many times

00:01:51 a folding to see if they can be used in real Electronics we send back to our collaborators in Taiwan they help us perform 200 000 sectors of voting I hope the result will get better but I didn't really expect it could survive like 200 000 Cycles 200 000 times and the electrical conductivity is still okay whereas for other systems the control system that

00:02:19 didn't have any graphing protection we folded them like 20 000 times and the electronic systems already broke down and so so it shows that graphene provides flexibility and it provides better electrical conductivity and also provides chemical stability for for the flexible Electronics gold is commonly used in biomedical

00:02:45 applications so we directly grow graphing on gold and we found that graphene protected gold is always good whereas Gold without graphing protection under the same kind of treatment degraded if we can mass-produce graphing with this approach we can also foresee other applications from semiconducting Electronics to wearable electronics for

00:03:11 biomedical applications to flexible Electronics in all kinds of other applications and also for Energy Research [Music]