Since then they’ve turned their conductive paint into pen form and developed various kits so that maker enthusiasts can paint their own circuits and make a whole plethora of interactive devices, our favourite being the Bare Paint light switch. Humans Invent spoke to co-founder Matt Johnson to explain how it all works.
Put simply, it is an electrically conducted paint. It is applied much like other paints or inks and when it dries it becomes electrically conductive. However, it gets much more interesting when you think about it more as paintable interactivity. You can do something really simple like draw a couple of lines and light up an LED but you can also use it to make an interactive surface and that’s what we think is really exciting.
How is it interactive?
The material can work as a capacitive sensor. That is not new technology at all, it is the same way a touch screen on most smart devices work but the difference being that here you can apply it to another material. You can imagine having the ability to interact with a computer through a piece of paper just by touching it and to us that is really exciting because it means that your interaction with technology can be through an interface or material that is appropriate to the information rather than the interface. In the next couple of months we are going to be showing off some interactive posters that we’ve built.
It gets much more interesting when you think about it more as paintable interactivity
The only way the material works is if you have some sort of component attached to it. Just like a wire, if you don’t plug it into anything it doesn’t do anything. With the posters, we’ve developed a specific piece of hardware but you can also connect to a battery for example.
Is the paint dangerous at all?
No, I guess you can say the same thing about a wire as well. As long as you stay within what we suggest as the field of use then it is not dangerous in the slightest. We tell people to stick to 12V DC or less. That’s mainly because we are working with hobbyists and students and it is a safe threshold within which they can work, but you can use a lot more voltage than that. It is also safe in terms of its material properties as it’s non-toxic and it’s water-soluble so it washes off really easily.
How does the Bare Paint light switch work?
That is a capacitive switch. The switch, which is a pad of paint, is being charged by a computer and when you touch it, it changes the charge. It is charging through your body but it is significantly less than if you got a piece of static off your TV when you try to turn it on. Obviously, you don’t feel it and that is literally the same way a touch screen on a smart device works as well, it changes the charge on the screen. So when you touch the light switch the signal gets sent to a relay which then turns the mains on and off.
You can imagine having the ability to interact with a computer through a piece of paper just by touching it
To be clear, the mains voltage is not going through the light switch, which in some ways makes it safer than a normal light switch and it certainly makes it easier to employ because, with a normal light switch, if you are going to redo your room, you have to decide exactly where it is going before you put the furniture in. But with this you can turn the whole wall into a light switch.
Are there any other products that you are working on?
The core product is the material and we started selling that in 2011 in just a jar. In May last year we started selling it as a pen. The pen has allowed the kit to develop and the kits seem to be breeding more kits that are much more sophisticated.
That was in 2009 when we had just graduated from the RCA. At that point the project was really focused on making material that would work on the skin but it hasn’t made sense for us to pursue that line of research. At that point we were interested in the material being used directly on the skin so we created a giant synthesizer made of dancers. When the dancers touched each other they would effectively close the circuit, so they would dance in sequence which would play the song.