Last week, MIT researchers published a blog post highlighting a paper detailing work on fully 3D printable electronics — namely a simple, semiconductor-free logic gate. The original paper was written by Jorge Cañada, a grad student in electrical engineering and computer science, and Luis Fernando Velásquez-García, a principal research scientist in MIT’s Microsystems Technology Laboratories.
Logic gates can be used for undemanding workloads including controlling the speed of a motor, and MIT researchers have proven that for such simple electronics, usage of 3D printing and a biodegradable copper-doped polymer can forego the need for semiconductors at such a small scale.
“The technology has real legs. While we cannot compete with silicon as a semiconductor, our idea is not to necessarily replace what is existing, but to push 3D printing technology into uncharted territory,” Velásquez-García said in the blog post. “In a nutshell, this is really about democratizing technology. This could allow anyone to create smart hardware far from traditional manufacturing centers.”
This project emerged purely by happenstance while the researchers were focused on another project, which was focused on fabricating magnetic coils using extrusion printing. This project used the same copper-lined polymer filament as the fully 3D-printable logic gates, and they realized that pushing electric current through could let it function as a simple transistor thanks to its level of electrical resistance. Polymers tested with materials besides copper, like carbon and graphene, could not provide the same results.
While these 3D printable logic gates are hardly a substitute for modern semiconductors, especially at scale, Velásquez-García says that “the reality is that there are many engineering situations that don’t require the best chips. At the end of the day, all you care about is whether your device can do the task.” Velásquez-García asserts, “This technology is able to satisfy a constraint like that.”
MIT includes a quote from Roger Howe, the William E. Ayer Professor of Engineering, Emeritus, at Stanford University, who says, “This paper demonstrates that active electronic devices can be made using extruded polymeric conductive materials. This technology enables electronics to be built into 3D-printed structures. An intriguing application is on-demand 3D printing of mechatronics onboard spacecraft.”