Electronic composites incorporate computing into physical materials, expanding the materiality of interactive systems for designers. In this research, we investigated acrylic as a substrate for electronics. Acrylic is valued for its visual and structural properties and is used widely in industrial design. We propose e-acrylic, an electronic composite that incorporates electronic circuits with acrylic sheets. Our approach to making this composite is centered on acrylic making practices that industrial designers are familiar with. We outline this approach systematically, including leveraging laser cutting to embed circuits into acrylic sheets, as well as different ways to shape e-acrylic into 3D objects. With this approach, we explored using e-acrylic to design interactive artifacts. We reflect on these applications to surface a design space of tangible interactive artifacts possible with this composite. We also discuss the implications of aligning electronics to an existing making practice, and working with the holistic materiality that e-acrylic embodies.
doi.org/10.1145/3613904.3642010
We introduce Painting Inferno, a novel method for controlling heat and stiffness using highly electrically conductive carbon nanomaterial heating paint. Heat has found widespread applications in thermochromic displays, shape-changing interfaces, haptic devices, and materials with adjustable stiffness. Although Joule heaters based on heating circuits using electrically conductive materials have been widely used, the complex design and fabrication processes limit the freedom to create custom heaters in scale, shape, and material. As an alternative Joule heating method, we explore the potential of carbon nanomaterial heating paints, which enable the rapid generation of uniform heat at low voltages. We present simple fabrication methods for creating handmade heaters using off-the-shelf materials and cutting machines and demonstrate the feasibility of crafting heaters with complex shapes and grid-array configurations. Leveraging the heating paint's compatibility with various materials, we showcase the versatile applications for interactive thermal displays, stiffness modulation devices, and pneumatic interfaces for stiffness-shape transformations.
doi.org/10.1145/3613904.3642226
Snap-through instability, like the rapid closure of the Venus flytrap, is gaining attention in robotics and HCI. It offers rapid shape reconfiguration, self-sensing, actuation, and enhanced haptic feedback. However, conventional snap-through structures face limitations in fabrication efficiency, scale, and tunability. We introduce SnapInflatables, enabling safe, multi-scale interaction with adjustable sensitivity and force reactions, utilizing the snap-through instability of inflatables. We designed six types of heat-sealing structures enabling versatile snap-through passive motion of inflatables with diverse reaction and trigger directions. A block structure enables ultra-sensitive states for rapid energy release and force amplification. The motion range is facilitated by geometry parameters, while force feedback properties are tunable through internal pressure settings. Based on experiments, we developed a design tool for creating desired inflatable snap-through shapes and motions, offering previews and inflation simulations. Example applications, including a self-locking medical stretcher, interactive animals, and a bounce button, demonstrate enhanced passive interaction with inflatables.
doi.org/10.1145/3613904.3642933
Rapid prototyping is an important tool for designers, but many fabrication techniques are slow and create bulky components requiring multiple machines and processes to achieve desired device shape and electronic functionality. Prior work explored ways to ease fabricating shapes or designing electronics, but we focus on creating shape and electrical pathways at the same time from a single material and machine. LaCir leverages a three-layered, laser-cuttable material to incorporate circuits into the structural substrate of the design using laser cutters. Our substrate features a layer of conductive material sandwiched between thermoplastic sheets, allowing designers to cut electrical traces and assembleable, 3D object geometry in a single pass. We evaluate different composite materials, weighing their cuttability, ease of assembly, and conductivity; we also show using fully laser-cut joints as structural and electrical connections. We demonstrate LaCir's flexibility through several example artifacts.
doi.org/10.1145/3613904.3642888
While recent work explores novel tools to make electronics and device design easier and more accessible, these tend to be either highly automated (great for novices, but limiting for more advanced users) or highly manual (suitable for experts, but imposes a higher skill barrier to entry). In this work, we examine a middle ground: user-guided design space exploration to bridge an intuitive-but-ambiguous high-level representation to a fully-specified, fabrication-ready circuit. Our system helps users understand and make design choices by sweeping the design space of alternatives for electronics parts (e.g., choice of microcontroller), marking invalid options, and plotting points to visualize trade-offs (e.g., for power and size). We discuss the overall system and its structure, report on the results of a small but in-depth user study with participants from a wide range of electronics backgrounds, and draw insights on future directions for improving electronics design for everyone.
doi.org/10.1145/3613904.3642009