A Cornell-based research team has made a crucial component for inflatable Braille technology.
Imagine an iPad or a Kindle for the blind, with inflatable Braille that changes shape under a user’s touch. The Cornell researchers developed a haptic array of densely packed actuators that cause silicone membrane “dots” to pop up when triggered by combustion.
According to Rob Shepherd, associate professor of mechanical and aerospace engineering in the College of Engineering and the paper’s senior author, one of the major hurdles for designing a dynamic Braille display for electronics is figuring out how to apply the necessary amount of force for each dot.
“Having something that can change its shape in a way you can feel, like real objects, doesn’t exist right now. There’s this tradeoff between having small actuators, and size and weight and cost. It’s so difficult,” Shepherd said. “Everybody’s been trying electromechanical systems. So we said, well, what if we don’t do that at all and we use combustion. Small volumes of gas can create powerful outputs.”
The Cornell team collaborated with researchers from Technion-Israel Institute of Technology to design a system consisting primarily of molded silicone and microfluidic liquid metal traces, in which liquid metal electrodes cause a spark to ignite a microscale volume of premixed methane and oxygen. In the array designed by the researchers, this fuel flows through the channels, leading to a 3-millimeter-wide actuator. Moreover, the whole system can be reset by a magnetic latching system.
This system does not comprise of electromechanical valves, and therefore, the actuators can be packed more densely together, resulting in a portable system that produces large displacements at high force in under 1 millisecond. The technology is also stretchable and could be incorporated into a range of applications, such as soft robots and wearable virtual reality equipment that simulates artificial touch.
The research appeared in the Proceedings of the National Academy of Sciences.