Description

Conventional CHEMFETs (chemical field effect transistors) are silicon MOSFETs with the gate uncovered to make it chemically sensitive. These gates, made of poly-silicon or metal which are replaced with a chemically sensitive metal, are widely used but are not very effective. Furthermore, due to inefficiencies in removing trapped charges/dipoles after a sensing event, CHEMFET sensors experience a lot of drift in their characteristics with regard to time.

The key difference from established silicon CHEMFET technology is that CHEMFETs use channel charge modulation by dipoles (which have a net charge of zero), whereas in our device we use trapped positive charges, which produce a much greater conductivity modulation. This results in a performance improvement of a factor of 10X to 100X in comparison with existing technology (tested with air-based analytes). A similar increase in sensitivity is expected to be obtained in other media as well. The invention covers inorganic-inorganic four-terminal devices for vapor/gas sensing, as well as inorganic-inorganic four-terminal devices for sensing in aqueous ambients

Benefits

• Outperforms traditional CHEMFETs by a factor of 10 in terms of magnitude of response
  
• Observed response in the chemical memory mode 10 to 100 times more intense
  
• Can run the sensor in many modes, multiparameter (3-in-1 sensor)
  
• Based on established technology
  
• Low cost, disposable, and easy to manufacture (combined with thin film technology)
  
• Suitable for various ambients
  
• Can be integrated at a system level for RFID applications
  

Features

• Given its advantages, this technology can still function as a traditional CHEMFET.
  
• The sensors can be refreshed after a sensing event.
  
• The unique sensing mode "both on" appears to be the most sensitive of all the multiple sensing mechanisms present.
  

Market Potential/Applications

Water testing, water quality monitoring, glucose level testing, lactic acid level monitoring, disease detection and diagnostics, and various industrial uses

Contact:

University of Texas,
Austin, USA
Website : www.otc.utexas.edu