How to Turn Copy Paper Into an Actuator

Carnegie Mellon University is pioneering paper usage in various ways. In 2018 a team from their Morphing Matter Lab came up with a technology able to turn normal copy paper into a thermoplastic actuator.

Paper is a highly versatile material thanks to the rich features it offers including folding, printing, and painting on its surface. So it comes as no surprise that paper increasingly enters areas no one ever thought it would, for instance, electrical engineering. However, until now a low-cost, easy to fabricate, flexible to customize, reversible, and electronically-controllable option for paper based actuators was still missing. But over the last year, researchers from Carnegie Mellon University (CMU) didn’t only succeed in teaching a normal piece of paper touchscreen abilities and designing furniture from paper, they also managed to print an actuator on common copy paper.

“Reinventing a Really Old Material”

CMU’s Morphing Matter Lab is known for pioneering approaches when it comes to opening up new fields for paper-based solutions, as Director Lining Yao confirms:

„We are reinventing this really old material. Actuation truly turns paper into another medium, one that has both artistic and practical uses.“

In order to provide common copy paper with conductive properties, they put a thin layer of off-the-shelf thermoplastic printing filaments (e.g. graphene polyactide composite) on it – with the help of an inexpensive 3D printer or even by hand. When an electrical current is applied, the thermoplastic heats and expands which makes the paper bend or fold into the desired shape. This process can also be reversed when the current stops causing the thermoplastic layer which then returns to its original shape. This video shows the incredible process:

The longer the lab members are doing their research, the more their imagination runs free: Besides printing touch and finger sliding sensors as well as bending angle detectors, the lab members also designed actuators using origami and kirigami forms:

“These enable the creation of structures that can turn themselves into balls or cylinders, or, they can be used to construct more elaborate objects, such as a lamp shade that changes its shape and the amount of light it emits, or an artificial mimosa plant with leaf petals that sequentially open when one is touched.”

New Opportunities for Paper Usage

As you can see, the method allows for many purposes. This is why the Morphing Matter Lab team already has big ideas and aims to try plastics and fabrics instead of paper. And they just took the next step by using the paper actuation technology to create 4D-printed objects.

In the future paper might also be used as an energy storage system: Thanks to Swedish manufacturer BillerudKorsnäs and researchers from Uppsala University it’s also likely that we use batteries made from paper soon, for example in smart packaging applications.

Despite our increasingly digitized world, an analogue medium like paper still plays a major role in our everyday lives due to its versatility and flexibility. Do you know of other techniques illustrating how technology can augment paper?