Stretchable rubber diode opens possibilities for medical, electronic devices

electrical circuits and systems fully out of rubbery materials.”

More flexible devices can behave more like biological tissue, allowing for better bio-integrated devices, according to Yu. An example may be a soft patch device that could be implanted on the heart.

“A heart beating will generate electric signals,” he said. “With a rubbery diode, a device could convert AC to DC within the body, which is not currently possible.”

To achieve such electrical performance while mechanically stretched, Yu said, the researchers rationally considered the device architecture, vertical structures and layout. In addition to benefits for more flexible medical devices, the development also has implications for power management systems in these medical devices toward self-sustainable systems.

“Energy scavenged from harvesters always needs to be rectified before the energy is stored for usage—and it’s important in many emerging fields,” Yu said.

Yu gave the everyday example of light-up sneakers, which contain a piezoelectric energy harvester to convert mechanical energy—a step—to electrical energy to light up the LEDs. A rectifying circuit converts the harvested AC electricity into useful DC power.

“Researchers and industry are using conventional diodes, but they want something that could be stretched, like what we report in the paper,” he said. “Such rubbery diodes open up many possibilities.”

Yu said that next steps include further optimizing the diode and integrating it into more complex systems.

“We’re looking to improve the diode architectures and performances and to achieve unperturbed operations even under very large extents of mechanical stretch or deformation,” he said. “We want to use these diodes to address critical device needs in various emerging applications such as robotics and biomedical devices.”