Design and fabrication of flexible capacitive sensor with cellular structured dielectric layer via 3D printing

May 11, 2021

Wenzhen Yang (1), Yu Liu (1,2), Wei Xu (1,3), Heng-Yong Nie (4,5)
IEEE Sensors Journal, 21, Issue 9, May 2021: 10473-10482. DOI: 10.1109/JSEN.2021.3060281


Flexible capacitive pressure sensor; 3D printing; sensitivity; cellular structure; dielectric layer


Because of high sensitivity, mechanical robustness, lightweight and wearability, flexible capacitive pressure transducer has been widely considered one of the most critical soft electronics in wearable consumables and e-skins. The enhancement of the pressure sensitivity of a flexible capacitive sensor relies on the introduction of interfacial microstructure to the dielectric layer. We demonstrate a new methodology to fabricate flexible capacitive sensors with copper-plated polyimide (PI) films as the electrodes and a porous polydimethylsiloxane (PDMS) layer 3D printed via the direct-ink-writing approach. Time-of-flight secondary ion mass spectrometry is developed to optimize the electroless copper plated PI films. What is further examined is the impact of the geometric complexity of the cellular PDMS structure, including filament width, spacing and alignment, on sensitivity, repeatability and reliability of the developed capacitive sensor. A robotic gripper equipped with our flexible pressure sensor showcases its competence to grip a soft target with well-posed force control. It is expected that our proposed sensor design and manufacturing methodology will advance the development of soft electronics and wearable sensors.

How Our Software Was Used

Dragonfly was used to process micro-CT data.

Author Affiliation

(1) School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China.
(2) Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, Jiangnan University, Wuxi 214122, China.
(3) Schneider Electric, Wuxi 214028, China.
(4) Surface Science Western, The University of Western Ontario, London, ON N6G 0J3, Canada.
(5) Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7, Canada.