Over the last few years, 3D printing has come a long way and has been used to create a wide range of items, including toys, furniture, and electronic components. As 3D printing equipment becomes more affordable, it could potentially also be used to fabricate soft electronic components for wearable devices.
Despite the promise of 3D printing for creating complex and flexible electronics, it has rarely been used successfully for this purpose. This is because solid-state elastic materials that can conduct electricity are difficult to print using existing inks.
However, researchers at the Korea Institute of Science and Technology have recently demonstrated the successful use of 3D printing to create elastic components that can conduct electricity. Their findings, published in a paper in Nature Electronics, could potentially pave the way for the large-scale printing of multi-functional and stretchable components for wearable devices.
The team achieved this breakthrough by developing a new emulsion-based composite ink. This special ink consists of liquid components dispersed within a conductive elastomer, which is a rubbery material that can conduct electricity.
“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,” explained the researchers.
The composite ink used by the researchers has numerous advantages over other inks commonly used in 3D printing. It exhibits viscoelasticity, shear-thinning, and lubricating properties, which better support the printing of complex 3D structures.
The researchers used their 3D printing approach and the emulsion-based ink to create elastic interconnects that they then used to create a wearable temperature sensor with a stretchable display. This device was found to perform well, and the same method could soon also be used to create various other stretchable and conducting components.
The researchers also highlighted the possibility of combining their approach with 3D scanning technologies to create soft electronics that are perfectly aligned with the shape of the human body and thus more comfortable for users to wear. In addition, the ink they created could inspire the creation of other emulsion-based inks that operate similarly but are based on different compositions and elastomers.
In conclusion, the Korea Institute of Science and Technology’s 3D printing approach and the emulsion-based ink they developed could revolutionize the field of soft electronics for wearable devices. It could potentially pave the way for the large-scale printing of multi-functional and stretchable components, making wearable devices more comfortable and effective.