Engineers at the University of California San Diego’s Jacobs School of Engineering have created a flexible, wearable device that measures not only biochemical but also electrical signals in the human body.

The Chem-Phys patch uses a flexible array of sensors and a small electronic board. It transmits biochemical and electrical signals via Bluetooth.

Patch includes custom circuits and screen-printed sensors. Image Credit UC San DiegoPatch includes custom circuits and screen-printed sensors. Image Credit UC San DiegoToday’s sensors typically measure a single signal, such as heart rate. The new sensor measures the heart along with chemical signals, including lactate. Combining the two signals could be of particular interest to athletes who want to improve their performance.

One challenge for the team was to assure that the discrete sensors didn’t interfere with each other. They used screen printing to create the patch on a thin, flexible polyester sheet that can be applied directly to the skin. The electrode that senses lactate was printed in the center, with two EKG electrodes flanking it.

Tuning the design to obtain a high quality signal, the team found about 1 ½ inches between electrodes was optimal. Then, to combat the potential disruption of the signal with human perspiration, a printed layer of a soft, water-repelling silicone rubber was added. This keeps sweat away from the EKG electrodes, but not the lactate sensor.

All the sensors were connected to a small circuit board with a Bluetooth low energy chip to transmit data wirelessly.

In addition to use by athletes, the ability to assess EKG and lactate simultaneously could potentially be applied to preventing and/or managing cardiovascular disease. The research team also plans to test adding sensors for other chemical markers and other vital signs