Graphene is flexible and conductive, rubber bands are stretchy and cheap, so what happens if you combine the two?
A discovery by Europeans scientists published this week shows a cheap and easy way to add graphene to rubber bands turning them into a sensor which could measure vitals such as your breathing or pulse rate.
In my radio live interview this morning I talked about the new technology, how simple it is and how it could be used:
The paper called “Sensitive, High-Strain, High-Rate Bodily Motion Sensors Based on Graphene–Rubber Composites” published in ACS Nano this week shows that adding graphene to rubber bands results in stretchy electronic properties. What is novel about this technique is how cheap they are to produce without expensive equipment or supplies and they show potential to be used as wearable sensors for monitoring breathing, heart rate, or irregular movements.
The process involves two simple steps, the first step is to create little sheets of graphene using a technique called liquid exfoliation where graphite is immersed in a solvent. The second step involves immersing rubber bands in toluene (commonly used as paint thinner) which causes them to swell and create large interparticle pores between the rubber and the natural latex particles in the band. This creates a space for the graphene to fit into naturally when the swollen rubber bands are dipped into the solvent graphite mix. Allowing the rubber bands to dry, reduces their swollen shape back to their normal size with the trapped graphene particles now inside.
When I read the experimental method described in this paper I was surprised that it was so easy I could probably carry it out at home in my kitchen!
The stretchy, conductive material senses motion such as breathing, pulse and joint movement and could easily be used to create a lightweight sensor which could be incorporated into a wearable band or even stretchy clothing for vulnerable patients who need constant health monitoring including premature babies. Because they are so cheap to produce, it opens up doors for patient monitoring in developing countries that may not be able to purchase more expensive and high tech sensors.