A Wireless, Passive pH Sensor Based on Magnetic Higher-Order Harmonic Fields
A new wireless sensor was fabricated for remote pH monitoring. The sensor was made of a magnetically soft film (sensing element) and a permanent magnetic film (biasing element) sandwiching a reversibly swelling hydrogel. When subjected to a low frequency magnetic AC field, the sensing element generated higher-order harmonic magnetic fields that could be detected with a remotely located detection coil. In the presence of a magnetic DC field (biasing field), such as that generated from the biasing element, the pattern of the higher-order harmonic magnetic fields varied depending on the field strength of the biasing field. The hydrogel, which acted as a transducer that converted variations in pH into changes in its own dimension, physically varied the separation distance between the sensing and biasing elements. This caused a change in the biasing field experienced by the sensing element, changing its higher-order harmonic field pattern allowing remote pH measurement. The advantage of this sensor technology is the wireless and passive nature, which allows its application for long-term pH monitoring in the human body. In this study, a pH-sensitive hydrogel was used for pH measurement. Nevertheless, this technology can be applied to a wide range of chemical and biological targets, provided the appropriate sensing coatings are employed.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
Document Type: Research Article
Publication date: 2009-08-01
More about this publication?
- The growing interest and activity in the field of sensor technologies requires a forum for rapid dissemination of important results: Sensor Letters is that forum. Sensor Letters offers scientists, engineers and medical experts timely, peer-reviewed research on sensor science and technology of the highest quality. Sensor Letters publish original rapid communications, full papers and timely state-of-the-art reviews encompassing the fundamental and applied research on sensor science and technology in all fields of science, engineering, and medicine. Highest priority will be given to short communications reporting important new scientific and technological findings.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites