IDTechEx recently visited the National Taipei University of Technology (NTUT) as part of our global ongoing research activities. NTUT has developed water based graphene composites, as opposed to most others which use organic solvents.
NTUT started work on graphene in 2014. They formulate graphene oxide from graphite. Usually when graphene is oxidized there is damage to the 2D structure, which impacts the conductivity of the bulk material. NTUT claim to have optimized the process to separate graphene layers while at the same time having minimal impact on each 2D layer in terms of creating holes in the layers. The graphene oxide is then reduced back to graphene. They then grow materials on the graphene, such as silver nano wires, silver nanoparticles, carbon nanotubes or zinc particles (used for linking with glucose oxidase for glucose monitoring). Many different composites can be made and over 50 have been developed so far.
This process is done in water which is a key differentiator, as opposed to using an organic solvent. NTUT have been granted a global patent for this. The key benefits of being water based is that the final product is biocompatible (organic solvents can cause irritation, for example). NTUT also claim that it is easier to grow other particles in water rather than in organic solvent.
The material can then be coated onto the substrate and heat pressed.
Given the excellent bio compatibility and that NTUT is heavily involved in the textile industry, targeted applications are for e-textiles. They have demonstrated heating textiles, ECG electrodes, glucose monitoring, TENS machines pads and also use the graphene as electrodes to assist with bone reconstruction (applying an electric field across the bone stimulates its growth).
NTUT seek to license their technology.
For more information see the IDTechEx report on Graphene, 2D Materials and Carbon Nanotubes: Markets, Technologies and Opportunities 2019-2029.