A Caltech Library Service

Wearable Microfluidic Diaphragm Pressure Sensor for Health and Tactile Touch Monitoring

Gao, Yuji and Ota, Hiroki and Schaler, Ethan W. and Chen, Kevin and Zhao, Allan and Gao, Wei and Fahad, Hossain M. and Leng, Yonggang and Zheng, Anzong and Xiong, Furui and Zhang, Chuchu and Tai, Li-Chia and Zhao, Peida and Fearing, Ronald S. and Javey, Ali (2017) Wearable Microfluidic Diaphragm Pressure Sensor for Health and Tactile Touch Monitoring. Advanced Materials, 29 (39). Art. No. 1701985. ISSN 0935-9648.

[img] PDF - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


Flexible pressure sensors have many potential applications in wearable electronics, robotics, health monitoring, and more. In particular, liquid-metal-based sensors are especially promising as they can undergo strains of over 200% without failure. However, current liquid-metal-based strain sensors are incapable of resolving small pressure changes in the few kPa range, making them unsuitable for applications such as heart-rate monitoring, which require a much lower pressure detection resolution. In this paper, a microfluidic tactile diaphragm pressure sensor based on embedded Galinstan microchannels (70 µm width × 70 µm height) capable of resolving sub-50 Pa changes in pressure with sub-100 Pa detection limits and a response time of 90 ms is demonstrated. An embedded equivalent Wheatstone bridge circuit makes the most of tangential and radial strain fields, leading to high sensitivities of a 0.0835 kPa^(−1) change in output voltage. The Wheatstone bridge also provides temperature self-compensation, allowing for operation in the range of 20–50 °C. As examples of potential applications, a polydimethylsiloxane (PDMS) wristband with an embedded microfluidic diaphragm pressure sensor capable of real-time pulse monitoring and a PDMS glove with multiple embedded sensors to provide comprehensive tactile feedback of a human hand when touching or holding objects are demonstrated.

Item Type:Article
Related URLs:
URLURL TypeDescription Information
Chen, Kevin0000-0002-6726-6132
Gao, Wei0000-0002-8503-4562
Javey, Ali0000-0001-7214-7931
Additional Information:© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Version of Record online: 18 AUG 2017. Manuscript Revised: 23 JUN 2017. Manuscript Received: 9 APR 2017. Y.G. and H.O. contributed equally to this work. This work was supported by the National Science Foundation (NSF) NASCENT Center. Y.G. acknowledges support from the China Scholarship Council (File No. 201406250097). H.O. acknowledges support from the Japan Society for the Promotion of Science (JSPS) Fellowship. H.O. acknowledges support from the JSPS Fellowship and Grant-in-Aid for Young Scientists (A). K.C. acknowledges support from the Robert Noyce Memorial Fellowship in Microelectronics. The authors thank James Bullock, Minghan Chao, Ziba Shahpar, Carlos Casarez, Matin Amani, Der-Hsien Lien, Colleen Forney, and Shyam Patel in University of California, Berkeley, and staff in SUPERNODE of University of California, Berkeley for their help. The authors declare no conflict of interest.
Funding AgencyGrant Number
China Scholarship Council201406250097
Japan Society for the Promotion of Science (JSPS)UNSPECIFIED
Robert Noyce Memorial FellowshipUNSPECIFIED
Subject Keywords:diaphragm pressure sensors, flexible pressure sensors, liquid metal, microfluidics, wearable
Issue or Number:39
Record Number:CaltechAUTHORS:20170920-150055300
Persistent URL:
Official Citation:Y. Gao, H. Ota, E. W. Schaler, K. Chen, A. Zhao, W. Gao, H. M. Fahad, Y. Leng, A. Zheng, F. Xiong, C. Zhang, L.-C. Tai, P. Zhao, R. S. Fearing, A. Javey, Adv. Mater. 2017, 29, 1701985.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:81639
Deposited By: Ruth Sustaita
Deposited On:20 Sep 2017 22:22
Last Modified:09 Mar 2020 13:18

Repository Staff Only: item control page