How will you feel if the whole dark room lit up or the ceiling fan start rotating instantly just if you touch the wall? It will be quite surprising, right? But you know, scientists always think little weird. They were not happy with the switch board at all, those hard circuits were very irritating so they started to think to print them or paint them on the wall. It sounds crazy, right? But this is the reality. Let’s see what they have thought and what they have invented finally.
In 2009, Isabel Lizardi, Matt Johnson, Bibi Nelson and Becky Pilditch wanted to investigate whether they could print an electrical circuit on to the body, eventually settling on an idea for an electric paint. After looking at the ingredients of existing conductive paints, the group examined how they could bind together a conductive powder into a paint – their first experience was copper powder in glue – and eventually came to a formula using carbon, a similar concept to the non-toxic paint. Early tests show the paint on skin being used as a conductor between a battery and a tiny bulb which lights up. London-based some companies makes paint that conducts electricity. It’s called electric paint and it can be used on a variety of surfaces including paper, plastic, wood, cardboard, or glass. These electric paint uses carbon to conduct electricity.
“Inside of this liquid, there are lots of small particles of carbon. When the liquid dries, those particles get closer together,” Bare Conductive CEO and cofounder Matt Johnson told Business Insider. “When the liquid dries, those particles get closer together over which the electricity can flow.” Electric paint is used with a circuit board which can then be connected to a computer or a switch. The paint acts as a sensor for the device.
Science Behind Conductive Painting
Electric Paint uses a combination of carbon black and graphite in a water-soluble solution to make a conductive water-based paint. It takes advantage of materials and binders used in the food industry to create a carbon ink formula that is solvent free and safe. Carbon is one of the elements, like oxygen or hydrogen, which in turn can take different forms, like diamond or graphite, charcoal or carbon black. Electric Paint uses two forms of carbon, carbon black and graphite to create the maximum conductivity along with the desired physical characteristics like flexibility and a viscosity appropriate for home use. The combination of carbon black and graphite make Electric Paint a “carbon paint”. The conductivity of a surface coated with Electric Paint depends on how the paint has been applied and the thickness of the coat. At a thickness of 50 microns, Electric Paint has a sheet resistance of 55 Ohm/square. As a general rule, carbon-based inks like Electric Paint have a higher resistance compared to silver paint or copper based inks. As a water soluble paint, Electric Paint can be thinned by adding water in order to change the viscosity of the material, however, this can affect the conductivity of the paint. Electric Paint dries at room temperature and requires no protective gear, ventilation or specialist equipment.
Capacitive Sensing and Conductive Painting
Capacitive sensing is a sensing technology that works through the generation of an electric field. This field can detect nearby objects by sensing any disruptions. Although you may not have heard the term, chances are you use this technology on a daily basis as capacitive sensing is the technology used on smartphone screens to detect touch. Capacitive sensing can also be used to detect proximity, making it easy to detect something without directly touching it. This is particularly useful for use-cases where gestures, movement or hygiene are important. When printed over a surface, and connected to the right hardware and software, Electric Paint can be used to create discrete, flexible, and large-scale capacitive sensors.
Although most people use the terms conductive ink and conductive paint interchangeably, there is a technical distinction between the two terminologies and a few different definitions. It’s generally accepted that paint is a material that is sprayed or brushed onto a surface and ink is a material which is printed onto a surface. Additionally, a paint typically describes a material which sits on the surface of a substrate, whereas an ink will penetrate the surface like ink on paper. As is probably now clear, the distinction between inks and paints isn’t always clear, but in general, when working within printed electronics, most materials are referred to as inks, due to the use of printing in manufacturing. So, this was a very short introduction of the conductive painting. Now what do you think? We are very close to the invention of the famous pencil of “ Shaka Laka Boom Boom”, aren’t we…..:P??
About the author: Shubhankar Kundu is pursuing BS-MS integrated degree in Chemistry from IISER Bhopal. He is a DST-INSPIRE fellow. In his leisure times, he loves writing poems and his is also a fantastic painter. He has a knack for music and loves to play violin. He also loves to recite Bengali poems and football is his most favourite game. Except this he is a die hard fan of Netaji Subhas Chandra Bose. Exploring unknown places and photography, these are his noteworthy hobbies. Shubhankar is one of the of admins and blogger of The Qrius Rhino.
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