Graphene Cells Generate Energy for Prosthetic Hands

At the Glasgow University, Scotland, a team of scientists has discovered a new use for graphene cells —the honeycomb form of carbon. They are using it to develop prosthetic limbs or more specifically, robotic arms with a sense of touch built-in.

The world over, several researchers and their teams are trying to make synthetic skin, which is flexible, and at the same time, has a sense of touch similar to the various types of sensory receptors the human skin possesses. At the Glasgow University, the scientists are powering an experimental form of electronic skin. They are using the power produced by solar cells made of graphene.

Although many types of prosthetic hands are available that can reproduce several mechanical functions of human limbs, the sense of touch is one not included yet. It would benefit the amputees a lot, if they could use a prosthetic hand that could sense what it touched, as this would be much closer to a real hand.

Such prosthetic systems do need clean electric energy, but providing that is hardly an easy task. However, the team of researchers from the School of Engineering at the University of Glasgow has discovered that by using ultra-thin honeycomb of carbon, also called graphene, they can generate the necessary clean power derived from the Sun.

Incorporating these clean energy generators in electronic skin with the sense of touch means robots can enhance their ability and performance when interacting with humans and detect potential dangers in a better way.

The team, led by Ravinder Bahiya, describes the process of integrating such photovoltaic cells made of graphene into the electronic skin, in detail, in the journal Advanced Functional Material.

Now the team is planning to use the same technology for powering other motors driving the prosthetic hand. According to the team, this is the only way they will be creating a prosthetic limb that is completely autonomous in its energy generation—something close to the normal limb.

Graphene Cells / Graphene Solar Cells

Graphene is actually a single layer of carbon atoms bonded together in a repeating pattern of hexagons. This structure makes it a two-dimensional material with amazing characteristics—a wonder material with extreme strength, flexibility, transparency, and astonishing conductivity. As it is made from carbon, a material abundantly available on the earth, graphene has the endless potential to improve existing products, while inspiring new ones.

Graphene’s superb transparency and conductivity make it an excellent choice for solar cells. However, although a great conductor in itself, graphene is not good at collecting the electrical current produced within the solar cell. While looking at alternative ways of modifying graphene for the purpose, scientists found graphene oxide (GO) to be more suitable for solar cells. Graphene oxide, although less conductive than graphene, is more transparent and a better charge collector.

Most organic cells generally use conductive indium tin oxide (ITO) and a non-conductive glass layer as their transparent electrodes. However, ITO is a brittle and rare substance that makes solar panels expensive. On the other hand, graphene as a replacement for ITO makes cheaper electrodes for photovoltaic cells.