Flexibility is a trait that will benefit everyone, whether you’re a new employee or a manufacturer of bendy straws.
Now, the same is true for prototyping of electronic devices. While designers typically test out their designs on “breadboards,” or thin plastic boards that can hold together electronic components, they are often stiff and slow. With the rigidity of these electronic backbones in mind, MIT researchers developed “FlexBoard,” a flexible breadboard that enables rapid prototyping of objects with interactive sensors, actuators, and displays on curved and deformable surfaces, such as a ball or clothes.
To illustrate the platform’s versatility on different items, researchers tested it out on kettlebells, video game controllers, and gloves, finding that sensors and displays can attach to the electronic components within each of its hinges. The team fitted LEDs and sensors into the kettlebells that detected if the users were performing their swing exercises correctly. The display would indicate red if the swing workout was done incorrectly or green if it was performed correctly, along with the number of reps. The platform’s feedback could be used to improve fitness routines in the future.
The breadboard’s design consists of a thin plastic that connects two pieces of the same material to enhance flexibility. This “living hinge pattern” can be found in the caps of condiment bottles and the spines of plastic disc cases, holding together FlexBoard’s electronic components. This design can be reproduced using a 3D printer that is available off the shelf, producing FlexBoards which can be sewn onto an item or attached by Velcro tape or epoxy glue.
This design allows for more rapid customization of interfaces. “A fundamental development in our modern world is that we can interact with digital content everywhere and anytime, which is enabled through ubiquitous interactive devices,” says research author Michael Wessely, a recent postdoc at the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) who is now an assistant professor at Aarhus University. “FlexBoard supports the design of these devices by being a versatile and rapid interaction prototyping platform. Our platform also enables designers to quickly test different configurations of sensors, displays, and other interactive components, which might lead to faster product development cycles and more user-friendly and accessible designs.”
FlexBoard also allows for virtual reality gaming to be enhanced by controllers or gloves. The team added a collision detection system to the controllers. This alerts players using VR headsets if they are in danger of bumping into objects. Sensors and motors were added to deformable gloves to capture gestures, influencing players’ in-game interactions.
The breadboards are reusable, adhesive and can be bent repeatedly in upward and downward directions. They will remain fully attached to prototypes that they were tested with. Wessely and the team evaluated FlexBoard’s durability by bending it 1,000 times, noting that the breadboards remained fully functional without breaking afterward. FlexBoard’s bidirectional flexibility allows it to attach to items that have curved designs. This makes FlexBoard an ideal prototyping tool for makers who are experimenting with new hardware and creating electronic items.
Users can either cut the long strips of breadboard into smaller segments or use several to prototype larger objects. For example, several FlexBoards could be wrapped around a tennis racquet, expanding the sensors’ range of detection when reading the speed of a volley.
The platform’s adaptability to different surfaces can streamline the electronic prototyping process. “While designing new interactive devices, user interfaces, or most electronic products, we usually treat the object form and electronic functions as two separate tasks, which makes it hard to test the prototype in its use environment in the early stage, and can lead to integration issues further down the road,” adds Junyi Zhu, MIT PhD student in electrical engineering and computer science and CSAIL affiliate. “FlexBoards tackle these issues with enhanced, reusable flexible breadboards, which accelerate the current interactive device prototyping pipeline, and provide a new and valuable prototyping platform for the low-power electronics design and DIY [do-it-yourself] community.”
FlexBoard will make future workout equipment, furniture, kitchen tools and other household products more interactive. The team does acknowledge that they need to optimize their platform, which requires improved bendability, strength, and durability via multi-material printing. FlexBoards can only be produced using FDM printers. These are 3D printing machines that are available on the market. They also limit the length of the boards and increase the time it takes to print them. These terminal strips require manual assembly, which makes prototyping bendable items difficult.
“As many researchers have investigated diversifying material properties, we questioned why the breadboard remains rigid,” says Donghyeon Ko, another author of the work who is a former MIT visiting PhD student from the Korea Advanced Institute of Science and Technology. “We wanted to make everyday objects ‘breadboard-able’ while developing shape-changing interfaces.”
Wessely Zhu and Ko co-authored a paper with Stefanie Müller, a CSAIL affiliated and associate professor at the MIT Departments of Electrical Engineering and Computer Science and Mechanical Engineering. Yoonji Kim is an assistant professor at the College of Art and Technology of Chung-Ang University. The team’s research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government, the Ministry of Education of the Republic of Korea, and the National Research Foundation of Korea.
In April, FlexBoard 2023 was introduced at the CHI Conference on Human Factors in Computing Systems.