21 February 2019
Flexible sensors for skin, brain
Published online 11 August 2016
Scientists make an array of out-of-plane sensors that can track the vital signs of the human body.
Vertically stacked three-dimensional sensors exhibit low resistance, and consume less power and space1.
The sensors are implantable and potentially useful for monitoring activities of brain cells, heart rates and body temperature.
Current techniques stack sensors horizontally with a lot of wiring. Besides taking up space, they generate noise that attenuates desired signals.
Researchers from King Abdullah University of Science and Technology (KAUST), Saudi Arabia, have overcome these shortcomings by vertically placing sensor electrodes and electronics through polyimide, a chemically inert and stable polymer on a silicon substrate. They connected the sensors with the electronics using copper on two sides of the same polymer.
Since the sensors and electronics are vertically stacked on the same polymer, this method shortens the wire length, decreases resistance, and reduces power consumption, communication delay and heat loss.
This technique also widens the distance between the sensed surface and the electronics that control sensors, preventing the sensed surface from being exposed to the heat dissipated by the sensor-controlling electronics.
“The array of sensors showed excellent sensing efficiencies when dipped in a saline solution that mimics biological fluid, suggesting their potential applications in healthcare industries,” says principal scientist Muhammad Mustafa Hussain.
- Hussain, A. M. & Hussain, M. M. Deterministic integration of out-of-plane sensor arrays for flexible electronic applications. Small http://dx.doi.org/10.1002/smll.201600952 (2016).