SAN FRANCISCO – What do musical instruments, car seats, and shoes have in common? Each item benefits from smart fabrics invented by Berkeley, Calif. company BeBop sensors. BeBop launched in October 2014 as the brainchild of musical instrument designer Keith McMillen who wanted to focus on novel measurements and charging methods.
“BeBop is a natural step for KMI, where we have diligently tuned fabrics, geometries, and production processes allowing us to ship over a million sensors,” founder McMillen said in a release. “All musical instruments are essentially sensors with forms of acoustic processing attached,” he said.
BeBop layers printed circuits onto polyester felts, synthetic silk weaves, and spandex of various thicknesses to create a web of sensors connected to sewn-in microcontrollers from Silicon Labs. Rather than measure speed or heartbeat, BeBop’s layered sensors can measure bend, location, motion, rotation, angle, and torque with applications from athletic clothing to smart insoles.
A BeBop prototype measures pressure in a smart insole. Source: BeBop
“We can build up layers to gather signals from different parts of the fabric,” McMillen told EE Times. “[Physical changes in the fabric] result in different amounts of electronics picked up by conductive inks on the surface, then brought to an embedded microprocessor.”
BeBop tested conductive inks developed by DuPont Microcircuit Materials, which act as a printed interconnect that is washable, temperature resistant, and stretchable. The inks can be applied to garments using silk screening.
BeBop develops smart fabric for OEMs and has done a great deal of research on smart insoles for shoes. BeBop’s basic insole has 20 pressure sensors in an array to create a map of gait and other actions, which could be used in medical markets to monitor diabetic and seizure patients.
“If you can measure pressure, you can measure velocity, then you can derive acceleration. It’s almost like a transistor as it’s a very basic electrical building block,” McMillen said. “By modifying the sensor mechanically, we can get bend from zero to 180 degrees, which is very useful for projects like data gloves.”
The insoles, which currently use USB, can transmit hundreds of bytes a minute, but McMillen would “like to really crank that up by factor of 10.” Insoles could also communicate over Bluetooth LE or Wi-Fi, depending on the data transfer needs.