Within Reach: Flexible Hybrid Electronics take wearable technology
to the next level
By Lou Fancher
UC Berkeley Electrical Engineering and Computer Sciences Professor Ana Arias is not easily persuaded to make predictions, but says in an interview the next generation of video gamers, chefs, industrial workers and any humans interacting with electronic devices will likely become “good at waving their empty hands in the air.” More importantly, people with prosthetic hands or those physically inhibited from making fine motor digital gestures will gain power and agency through the use of a new device that combines wearable biosensors with artificial intelligence software. Known in the biotech industry as Flexible Hybrid Electronics, the wearable devices that wrap around human limbs like cloth are expanding beyond medical use to include consumer, industrial, military, agricultural, environmental and aviation applications. In 2019, the FHE market was valued at $95 million, according to some experts. Market research reports forecast FHE valuation will increase to $231 million by 2025.
Arias earned both a bachelor’s and a master’s in physics from the Federal University of Paraná in Curitiba, Brazil. In 2001, she completed her doctorate in physics from the University of Cambridge in the U.K. Joining UC Berkeley in 2011, she is now faculty director of the Berkeley Emerging Technologies Research Center and the Berkeley Wireless Research Center. The FHE project involving her Arias Research Group as the primary research lab is a collaboration with NestFlex, the Silicon Valley-based Flexible Hybrid Electronic Innovation Institute, and is sponsored by the Air Force Research Laboratory.
Arias, and the team she leads, developed the bio-sensing system that consists of an array of 64 electrodes screen-printed with conductive silver ink on Polyethylene Terephthalate substrate. It uses advanced AI and a hyperdimensional computing algorithm to train computers to recognize 21 specific hand gestures. In simple street language, the group developed a flexible sleeve/armband that, when worn, responds to a person pointing, making a fist, holding up fingers as if counting, giving a thumbs-up and other common gestures, causing a computer in real time to read and understand the information … and then take action through a video game controller, operate a remote controlled car, manipulate a robotic device, “type” on a keyboard and more.
“The main idea to developing the EMG electrodes—electromyographic electrodes measure electrical activity in response to a nerve’s stimulation of muscle—was to train sensors to recognize muscle activity so you could train a prosthetic arm or any prosthetic limb. That was the motivation for the research,” Arias says. “But, of course, if you can control an artificial limb, you can also control other objects, like video game controllers or remote controls operating cars or robotic arms used in manufacturing. I don’t see why playing the piano wouldn’t be an application. Could you wear the sensor to operate heavy machinery more safely? Absolutely. Workers could be wearing the sensors and controlling the machines just with movements. Like the idea of playing the piano, once you have fine control of gestures, you can use gestures to control other things without touching them.”
Arias grew up in Brazil and loved mathematics. “It made my brain excited,” she says, laughing. When she encountered physics in high school, she says, “I fell in love with it. It was the perfect science to explain physical phenomena with math concepts.” While earning her masters in Brazil, she was introduced to the then-new field of organic electronics. “I did my research in that area, because the materials are much cheaper than silicon, so you can make [electronic parts] at lower costs. I was interested in that aspect because in Brazil, so many people don’t have resources and access to energy. By applying semiconductor applications to solar cells, I could help the energy problem for people with low incomes.”
FHE technology is also additive, meaning the manufacturing process uses the materials only where they are needed. Silicon technology is subtractive; material is deposited everywhere, then taken away and the excess discarded as waste. Structures built using the printed flexible approach therefore reduce waste, use less materials and less power to produce, and are thinner, more lightweight. It might be years before the slim, bendable results based on current prototypes are found in cell phones and automobiles, or integrated into clothing and wearable devices like wristwatches or personal health monitors, but as manufacturing and material costs drop and technology improves, broad market adoption is likely.
“I think it will make its way even to fashion, once it is more mainstream and there are companies producing it in large volume,” Arias says. “In our project, we bring the electronics to a place where they feel invisible to the user. Instead of holding something, you’re wearing it and performing movements without thinking you are wearing electronics. The FHEs are becoming like an accessory part of clothing. It integrates the computing with a person in a comfortable, friendly way. My students were super excited because they could wear it the whole day: wearability was a big point for them. It was intuitive and their hands were then free to do something else.”
The devices hold immediate value not just for people who have prosthetic hands, but for anyone who has lost dexterity due to injury or other conditions. During rehabilitation the technology can help therapists and doctors identify a patient’s weakest muscle movements. It can be used to discover methods for practicing alternative movements to regain ability after the range of movement is established, according to Arias. “Is it a big muscle, a tiny muscle?” she asks. “Is it originating in a little finger or the thumb? The sensors have high resolution so you can pick up the subtleties in movement.” Importantly, FHEs can be customized. “I can get a sensor that is designed for my arm with the number of sensors that will fit. Right now, available devices offer only off-the-shelf type things with big electrodes. It doesn’t matter if you are a child or a 6-foot-five-inch man, you get the same device. One of the fundamentals of FHEs is that we can move off the model where everyone gets the same treatment.”
Expectedly, because of her early interests in organic electronics, the Arias Research group is also exploring agriculture applications. Sensors deployed in large fields can monitor the contents of fertilizer and water with high specificity. Aimed at improvements in yield production, the technology might be used to discover where water is flowing, or measure nitrogen in the soil that pollutes water supplies and reduces environmental safety and crop sustainability. “A good application is one where you need high volume, low price and electronics used over a large area. I wanted to have a way to quantify greenhouse gas emissions by monitoring the soil and the air,” she says.
Asked to step out on a limb with predictions about the impact of FHEs on future jobs, she says, “I think the jobs will be different. It’s an opportunity to train the next generation for jobs that are less repetitive, more creative and not mindless work. Maybe the users will be teachers in classrooms, or engineers creating new electronics. Maybe they’ll be chefs using the technologies and doing creative things that are enjoyable to perform.”