Inflation of the silicone membrane “dots” by combustion of gas can be used to create a Braille display for use in various electronic devices.
Imagine an iPad or Kindle for the blind, with an inflatable Braille screen that changes its surface shape when the user touches it. A research team led by experts from Cornell University has developed a similar technology: a set of tightly closed mechanisms that, when starting mini-combustion processes, create bulging “points” in the silicone membrane.
One of the major hurdles in designing a dynamic braille display for electronics is figuring out how to apply the right force to each point. Previous attempts typically used miniature motors, hydraulics, or connected micropumps, but all of these mechanisms are cumbersome, complex, and expensive, according to Rob Shepard, an assistant professor of mechanical and aerospace engineering at the university’s College of Engineering.
To make the system smaller and cheaper, Cornell’s team worked with researchers at the Technion Israel Institute of Technology to develop a system of molded silicone and liquid metal electrodes that spark to ignite the premixed methane and oxygen.
This “fuel” passes through a series of independent channels, each of which leads to a 3 millimeter thick membrane. Rapid combustion causes the thin silicone membrane to swell at the desired point. The magnetic closure system gives these points a permanent shape. The entire system can be reset to default with a simple click.
The system currently consists of nine “dots”, but the researchers hope to scale the development and eventually create a complete electronic tactile display.