We've already heard about conductive inks that allow electrical circuits to be hand-drawn onto materials, using a ballpoint pen. Scientists have now developed a new such ink, which they claim is cheaper and more functional than others.
Besides being expensive, existing conductive inks often clog up the tip of the pen, plus some of them may degrade over a relatively short time. Led by So Yu Liao and Jun Qian, researchers from China's Wuhan University set out to create an ink that lacked those problems.
The water-based ink that resulted contains conductive carbon particles, made up of graphene nanosheets, multi-walled carbon nanotubes and carbon black. A resin known as maleic anhydride modified rosin serves as a viscosity-reducing binder, while xanthan gum stabilizes the dispersion of the particles within the ink, keeping them from settling to the bottom.
Additionally, the particle size was optimized relative to the tip of the pen, ensuring they were small enough to pass through without clogging.
The scientists have used the new conductive ink to draw electrical circuits on a variety of both flat and irregular surfaces, including a loofah sponge. Circuits drawn on paper remained functional after multiple folding cycles, plus the ink itself remained stable and usable after sitting for 12 hours. It additionally emitted no harmful gases, and should be considerably cheaper to manufacture than other conductive inks.
It is hoped that once developed further, the ink could even be used to draw circuits on human skin.
The research is described in a paper that was recently published in the journal ACS Applied Electronic Materials.
Source: American Chemical Society