Bendable, Stretchable Batteries Provide a Jump Start for Wearable Tech
The integration of electronics in everything we carry is the fashion trend of the future. However, these LED indicators, health sensors, heating and all we are going to propose need power devices. A battery is a logical solution, but it has been difficult to design a robust and effective solution, but also comfortable.
However, in a study published in the journal Science Advances, a team from the University of California, Berkeley, describes a battery that can meet all these parameters.
The battery consists of springs and is charged by an integrated solar cell. The unprecedented tolerance of the battery to repeated flexing and ability to bend in any direction that is suitable for integration into portable electronic devices such as health monitors.
Aminy Ostfeld, a postdoctoral fellow in Berkeley, says the project has emerged from the question, “What is the limiting factor for a person’s comfort?” On today’s mobile devices. Even small battery clocks, according to Ostfeld, “see large, heavy and uncomfortable” flexible sensors near the cutting edge of technology.
The cells are composed of several major components: an anode, a cathode and an electrolyte. Commercial battery models, such as lithium-ion, are made of two solid electrodes and a liquid electrolyte. None of these components have remarkable intrinsic elasticity, and attempts to manufacture them from softer materials have so far cost the battery much.
In this new battery, rigid metallic components are rolled up in coils (springs), which overlap each other. The resulting battery resembles a long, thin stealth.
“This battery design gives us a lot of options,” says graduate student Alla Zamarayeva, lead author of the article. The stamp and spring size can be customized for a variety of applications.
“Security is a major design consideration,” said Zamarayeva, when wearing the device. The design of the silver-zinc stack was chosen for its energy density and non-toxic materials. Zamarayeva said he hopes to move the production of battery components that are safe and biodegradable.
“The elimination of all these mobile devices will become a problem … we have to look forward and anticipate this,” he said.
A solar cell designed by Ostfeld was also made in a flexible and daylight way in mind. Setting up a power supply to the battery is “a big step that people really do not appreciate,” says Zamarayeva.