Mist‑Based Aerosol Jet Printing Puts Circuits on Curved 3‑D Surfaces

Imagine being able to spray a circuit onto a ball, a wing‑shaped panel, or even a satellite antenna – no flat board needed. That’s exactly what a team from Iowa State University is doing with a technology that sounds like it belongs in a sci‑fi lab: aerosol‑jet printing.

Unlike your everyday ink‑jet printer that jets droplets of ink directly onto paper, aerosol‑jet printers first turn a liquid ink into an ultra‑fine mist. A stream of carrier gas pushes that mist through a tiny nozzle, letting it deposit features as small as 10‑100 microns. In plain English, it’s like spraying a cloud of conductive paint with laser‑level accuracy.

What makes this effort stand out is the marriage of that mist‑jet with a six‑axis robotic arm. The arm can swivel, bend and reach around objects that are anything but flat. The researchers have written custom software and added real‑time vision feedback so the nozzle knows exactly where it is, even when the surface twists like a pretzel. It’s a bit like teaching a robot to write on a basketball while it’s still rolling.

“Right now, the work that’s getting me excited is the conformal printing,” says Ethan Secor, the associate professor spearheading the project. “For the next two to three years, that’s going to be a big effort.” He and his co‑founder, former graduate student Jeremy Rurup, have turned this lab work into a startup called Contour Circuits, which is already pulling in funding from NASA and the National Science Foundation.

Beyond the wow factor, the team is wrestling with very practical challenges. Printing on a curve means the ink has to stick, cure, and stay functional even as the substrate bends or experiences temperature swings – think of a sensor on a jet engine or a rover on Mars. To that end, they’re testing new ink formulations that can survive extreme heat‑cold cycles and the harsh radiation of space.

Potential applications ripple across several fields. In energy, you could imagine solar‑tracking panels that wrap around a wind turbine blade. In health care, flexible patches that conform to a patient’s skin could monitor vitals without bulky rigs. Aerospace and defense folks are eyeing the ability to embed antennas directly onto aerodynamic surfaces, trimming weight and improving reliability.

Secor’s journey into printed electronics started with graphene inks at Northwestern University, then meandered through liquid‑metal circuits, microsupercapacitors and even lithium‑ion batteries. He eventually grew tired of using off‑the‑shelf printers, opting instead to build his own machines. “I learned how to build a printer and that opened up a lot of research directions,” he says, smiling. “Now we can open the black box, poke around, and make it do things no one thought possible.”

The future, according to the team, isn’t just single‑material prints. They’re experimenting with multi‑ink deposition, a bit like moving from black‑and‑white printing to full‑color grayscale. By varying the composition of each droplet on the fly, they could fine‑tune electrical conductivity, flexibility, or even magnetic properties across one curved component.

All of this is still early days, but the combination of mist‑based deposition, robotics, and smart materials is already pointing toward a world where electronics can hug any shape – from a curved smartphone screen to the hull of a spacecraft. If you’ve ever wondered what the next generation of wearable or space‑grade sensors might look like, they’ll probably be printed, not soldered, and they’ll probably be on a surface you never expected.