Advances in Engineering Advances in Engineering features breaking research judged by Advances in Engineering advisory team to be of key importance in the Engineering field. Papers are selected from over 10,000 published each week from most peer reviewed journals.
Significance Statement
A new sensor has been developed by engineers at Stanford that is made of a special rubber layer between two strips of copper that act like radio antennas; the rubber is an insulator. Pressure squeezes the antennas infinitesimally closer, altering the electrical characteristics of the device. Radio waves beamed through the device change frequency as pressure changes, providing a way to gauge pressure wirelessly. The underlying technology has already been tested in small animals. It has the potential in the future to be used prosthetic devices with an electronic sense of touch.
Nature Communcations. 2014 ;5:5028.
Chen LY1, Tee BC1, Chortos AL2, Schwartz G3, Tse V4, Lipomi DJ3, Wong HS1, McConnell MV5, Bao Z3.
[expand title=”Show Affiliations”]1Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA.
2Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA.
3Department of Chemical Engineering, Stanford University, 381 North South Mall, Stanford, California 94305, USA.
4Department of Neurosurgery, Kaiser Permanente, Redwood City, California 94063, USA [2] Department of Neurosurgery, Stanford University, Stanford, California 94305, USA.
5 Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA [2] Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305, USA.
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ABSTRACT
Continuous monitoring of internal physiological parameters is essential for critical care patients, but currently can only be practically achieved via tethered solutions. Here we report a wireless, real-time pressure monitoring system with passive, flexible, millimetre-scale sensors, scaled down to unprecedented dimensions of 1 × 1 × 0.1 cubic millimeters. This level of dimensional scaling is enabled by novel sensor design and detection schemes, which overcome the operating frequency limits of traditional strategies and exhibit insensitivity to lossy tissue environments. We demonstrate the use of this system to capture human pulse wave forms wirelessly in real time as well as to monitor in vivo intracranial pressure continuously in proof-of-concept mice studies using sensors down to 2.5 × 2.5 × 0.1 cubic millimeters. We further introduce printable wireless sensor arrays and show their use in real-time spatial pressure mapping. Looking forward, this technology has broader applications in continuous wireless monitoring of multiple physiological parameters for biomedical research and patient care.
