Inflating "dots" of silicone membrane by burning 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 surface shape when the user touches it. A research team led by Cornell University has developed a similar technology: a set of tightly sealed mechanisms that create convex "dots" in a silicone membrane when triggered by mini-burning processes.
One of the major obstacles in developing a dynamic braille display for electronics is figuring out how to apply the right force to each dot. Previous attempts have typically used miniature motors, hydraulics or connected micro-pumps, but all of these mechanisms are cumbersome, complicated and expensive, according to Rob Shepard, associate professor of mechanical and aerospace engineering in the university's College of Engineering.
To make the system smaller and cheaper, Cornell's team worked with researchers at Israel's Technion Institute of Technology to develop a system of molded silicone and liquid metal electrodes that trigger a spark to ignite pre-mixed methane and oxygen.
This "fuel" passes through a series of independent channels, each of which leads to a 3-millimeter-thick membrane. Rapid combustion forces the thin silicone membrane to swell at the right point. A magnetic closure system gives these points a permanent shape. The entire system can be reset to the default state with a simple push.
The system currently consists of nine "dots," but researchers hope to scale up the development and eventually create a full-fledged electronic haptic display.
Illustration: Cornell University