Conductive HCR with Graphene Nanotubes for Medical Devices

A new conductive heat cured rubber (HCR) enhanced with graphene nanotubes from OCSiAl combine functionality and comfort for materials used in medical devices. The compound has been used for serial production of electrical massage treatment devices.

Graphene nanotubes have been shown to be a game changer in the materials industry when an application requires electrically conductive properties. They outperform other conductive materials for silicone rubbers used in skin-contact applications such as carbon black and silver particles. While silver-based additives have unresolved problems with mixing and processing, carbon black leads to skin contamination, as well as to degradation of the properties of silicone that are crucial for healthcare applications, such as flexibility and softness.

The use of graphene nanotubes, also known as single wall carbon nanotubes, allows silicone producers to combine functionality and comfort in materials used in medical devices. The growing requirements of the electrical massage devices industry resulted in a necessity for conductive silicone rubber that maintains high softness and flexibility. Graphene nanotubes became the solution for a Chinese silicone rubber compound manufacturer. Nanotubes make it possible to pass massage pulses through rubber to the human body, while maintaining the desired original properties of the silicone.

A dosage as low as 0.25% of OCSiAl’s nanotubes replaces up to 40% of carbon black in a conductive HCR (high consistency rubber) silicone compound, ensuring stable volume resistivity of <100 Ω•cm. It shows no carbon release to the material’s surface and no contamination of the skin. This tiny dosage of strong, highly-electrically conductive, and flexible nanotubes reportedly does not impair the silicone’s softness or elasticity,and makes it possible to maintain other mechanical properties. OCSiAl’s industry-friendly forms of nanotube concentrate based on silicone-compatible carriers allow manufacturers to retain standard production processes, which is not achievable when applying silver-based additives.

The new silicone compound is used in the production of a serial line of electrical devices for massage treatment. Compliance of the nanotube compound with the EU RoHS Directive, along with the fact that OCSiAl’s nanotubes are the only single wall carbon nanotubes registered under the European REACH regulation, has allowed the manufacturer to enter the European market and further expand its line of products using the new nanotube silicone compound.