Over the past few years, three-dimensional (3D) printing has gotten more sophisticated and has been effectively applied to produce a wide range of products, such as electronic components, toys, and furniture. The fabrication of soft electrical components for wearable technology may also be possible with the advent of more reasonably priced 3D printing equipment.
Even though 3D printing holds great potential, it hasn’t been able to create intricate and flexible circuits very often thus far. This is due, in part, to the difficulty of printing solid-state elastic materials with electrical conductivity with current inks.
Recently, researchers at the Korea Institute of Science and Technology successfully used 3D printing to produce elastic electrically conductive components. Their suggested printing technique, described in a report published in Nature Electronics, may open the door for the large-scale printing of stretchy and multipurpose wearable device components.
The team’s development of a novel emulsion-based composite ink made it possible for them to manufacture elastic conductors using 3D printing. This unique ink is made of liquid ingredients distributed throughout a rubbery substance called a conductive elastomer, which conducts electricity.
Byeongmoon Lee, Hyunjoo Cho, and colleagues said in their study that “printing solid-state elastic conductors with three-dimensional geometries is challenging because the rheological properties of existing inks typically only allow for layer-wise deposition.”
We demonstrate the omnidirectional printing of elastic conductors using an emulsion system made up of an immiscible solvent, an emulsifying solvent, and a conductive elastomer composite. The composite’s viscoelastic qualities give printed features structural integrity, enabling the direct writing of freestanding, filamentary, and out-of-plane three-dimensional geometries, as well as pseudo-plastic and lubricating behaviors that stabilize printing and guard against nozzle clogging.”
When compared to other inks frequently used in 3D printing, the researchers’ composite ink offers a number of favorable qualities. Its viscoelasticity, shear-thinning, and lubricating qualities, in particular, provide enhanced support for the printing of intricate three-dimensional structures.
In their publication, Lee, Cho, and associates said that “Printed structures of the intrinsically stretchable conductor exhibit a minimum feature size less than 100 μm and stretchability of more than 150%.” “The vaporization of the dispersed solvent phase in the emulsion results in the formation of microstructured, surface-localized conductive networks, which improve the electrical conductivity.”
The researchers created a wearable temperature sensor with a stretchy display by printing elastic interconnects, which they then utilized to illustrate the possibilities of their 3D printing method and the emulsion-based ink they designed. It was discovered that this apparatus operated effectively, and in the near future, new stretchy and conducting parts might be made using the same technique.
In their study, Lee, Cho, and associates discuss how their method could be combined with 3D scanning technology to produce soft electronics that are more pleasant for people to wear since they are precisely matched to the contours of the human body. Furthermore, the ink they developed might serve as a model for the development of alternative emulsion-based inks with comparable functionality but distinct compositions and elastomers.