LaCir

Wouldn’t it be cool if you could make an interactive device on a laser cutter, in one go, without having to solder wires or design a separate PCB? That’s exactly what LaCir is for. LaCir is a technique that lets you build both the physical shape and the circuitry of your device from a single material, using just a laser cutter. You read that right—LaCir enables you to prototype full 3D shapes with embedded circuits by cutting and folding a custom multilayer material.

The LaCir material stack is made up of three layers: two plastic structural sheets sandwiching a conductive middle layer. Using a combination of laser cut types—some to slice all the way through, others to just expose or trace the conductive layer—we can lay down circuit paths, define the shape of our object, and even make structural joints that are also conductive. The best part? You don’t need to modify your laser cutter or buy anything fancy. If you’ve got access to a standard CO₂ laser cutter and some silver paint or copper tape, you’re ready to go.

We tested a whole bunch of materials and setups to make LaCir reliable and versatile. It works well with acrylic, Delrin, and even wood as the outer structure, and you can use things like silver paint, conductive mesh, or copper tape in the middle. Once you cut your object, you fold it up, just like any laser-cut box—but this time, you’re folding up a circuit too.

How does it work? Link to heading

Laser cutters are great at turning flat materials into 2D and folded 3D shapes. But what they usually don’t do is create working electronics as part of the structure—at least not without modifying the machine or switching materials mid-process. LaCir changes that by introducing a laser-cuttable multilayer substrate that embeds a conductive layer between two structural layers. With the right kinds of cuts, we can selectively expose, route, and connect the conductive layer, turning the shape itself into a circuit.

The key lies in four types of cuts we developed to manipulate the material: - Through Cuts slice through all layers and are used to define object outlines or completely separate sections, both physically and electrically. - Tracing Cuts go through the top structural layer and the conductive layer but leave the bottom layer intact. These are used to define circuit paths—like routing a wire inside the material. - Tracing Cuts with Heal are a clever trick: after making a tracing cut, we apply a slightly offset second pass that melts the plastic back over the conductive layer. This protects the trace and gives it more mechanical strength. - Revealing Cuts only remove the top structural layer, exposing the conductive layer underneath without altering it. This is useful for contact points, pads, or electrical connections to external components.

These cuts are simple vector lines that you can lay out in your favorite CAD tool. By carefully planning which layer gets cut—and how deep—you can design both the physical shape and the embedded circuit at the same time. And because LaCir works with unmodified laser cutters, it’s fast and accessible.

But what about assembling the object? LaCir supports joints that aren’t just structural but also conductive (!). We experimented with several types of laser-cut joinery—snap-fits, tabs, screws, magnets—and showed that you can route electricity right through these joints. You can even embed regular screws or magnets into the cuts to get both a mechanical and electrical connection. It’s surprisingly robust, and super satisfying when it clicks together and lights up.

LaCir devices are fast to make and easy to experiment with Link to heading

Prototyping interactive objects usually means going back and forth between shape design and circuit design. With LaCir, you do both at once. You can laser-cut an object with joints and traces in a single pass, fold it together in a couple of minutes, and it just works. Want to change a sensor position? Just move your tracing cut. Need to test a new enclosure shape? Tweak your DXF and re-cut.

We made a few example devices using LaCir: a musical box that connects through conductive joints, a physical menu selector with embedded paths, and more. In each of them, the structure is the circuit—no separate breadboard, no soldering, no fuss.

So, if you’re into interactive devices and love the idea of prototyping them faster, cleaner, and with less hassle, LaCir might be just what you’re looking for.

You can download this paper from the ACM Digital Library, or directly from this website.