Shape-changing displays offer a uniquely embodied and highly aesthetic mode of computer-human communication, perfect for uses such as ambient displays, embodied avatars, interactive art, and educational experiences. By giving elements form, these applications can become more engaging with increased physicality. However, practical shape-changing displays continue to be elusive, and there is considerable ongoing research in this area, both in the HCI community and beyond. Ideal approaches might be considered to have the following properties: low-cost, fast-actuating, silent-operation, compact, robust, and easy to fabricate.

In this work, we describe ElectriPop, a new fabrication workflow and computational tool that allows sheets of metalized mylar to be cut and then “inflated” into complex 3D forms using electrostatic charge. This is achieved by carefully placing and nesting various cuts, slits, and holes such that mylar elements repel from one another. We provide a brief primer on the principles of our technique’s operation. Of course, this introduces interesting design challenges, such as how to assist designers in the creation process given the complex 2D-to-3D transformation process. For this, we developed a simulation tool that runs in parallel with existing vector editing programs that simulates the 3D output. In a design study we conducted, participants found that the real-time visualization greatly facilitated rapid prototyping of forms.

Unlike more exotic shape-changing technologies, our technique involves only a single sheet of thin film, and is compatible with industrial and hobbyist manufacturing processes, including die cutting, laser cutting, vinyl cutting, and even just handheld exacto-knives and scissors. Given that mylar film costs <$1 USD per square meter, this means we can create 3D objects for just a few cents each, opening new uses in consumer objects. In addition to being easy to fabricate and low cost, our technique is also fast-actuating, requires little power to stay inflated, and the operation is nearly silent. We do, however, require an external electrostatic generator to actuate our designs. We built two proof-of-concept actuation bases, both costing under $10 USD. To help illustrate the rich creative potential of our method, we fabricated a series of demos, ranging from pop-up books to smart speaker avatars. All of our tools and designs are open sourced to bootstrap makers interested in experimenting with our technique.

Research Team: Cathy Mengying Fang, Jianzhe Gu, Lining Yao, and Chris Harrison