Graphene nanotubes pep up silicone healthcare sensors

Luxembourg – Graphene nanotube supplier OCSiAl has collaborated with a Chinese polymer compounder to develop a material that meets the requirements of flexible and conductive silicone-based electrodes and sensors for the medical industry. 

By introducing graphene nanotubes to the silicone, the Chinese compounder enabled a volume electrical resistivity of below 10^2 ??cm with low hardness and high elasticity, said OCSiAl in a recent statement.

The additive, it said, addressed drawbacks of traditional conductive additives such as carbon black, metal fillers, or carbon fibers, which had significant impact on the silicone’s flexibility, hardness, processing, purity, and overall pricing.

An important feature of the silicone compound is that it does not leave marks on contact with skin, and it is produced without the dust that is typical for the use of carbon black as a conductive additive, OCSiAl said.
 
Another end-use product, said OCSiAl, is an electronic impulse massage device, which features graphene nanotubes introduced into HCR (heat cured rubber) silicone.

The additive, according to OCSiAl, gave the rubber volume resistance of <300 ? with no carbon release to the surface, while maintaining mechanical properties such as softness. 
 
“Graphene nanotubes have a greater length-to-width ratio than any other material,” said Ekaterina Gorbunova, development and support leader for elastomers, VP, OCSiAl Group.

"Together with their super-conductivity and strength, this allows nanotubes to form electrically conductive 3D networks inside elastomers," she explained. 

According to the expert, a 0.01% working dosage for nanotubes gives them the edge as it is “tens or even hundreds” of times lower than that of other additives.

“Our partners can now manufacture flexible, soft, but conductive silicone compounds, with a reduced price of properties,” she said. 

A striking example, said Gorbunova, is a recently launched ‘cyber hand prostheses’ with a 10- to 15-times reduced cost for a touchscreen use function.

The fingertips of the prostheses hand are equipped with graphene nanotube-reinforced conductive silicone, she added.