pH ISFET Sensors

ISFET (Ion Sensitive Field Effect Transistors) are non-glass pH electrodes. Their fabrication with microelectronic technologies offers advantages like robustness, small size and low cost compared to standard pH glass electrodes. 

IMB-CNM fabricates several designs of ISFETs. These contain SiO2 gate membranes for measuring pH.


Detail of a encapsulated ISFET sensor


  • Standard NMOS based technologies.
  • Fully CMOS compatible technology with on chip circuit integration.
  • Biocompatible and Organic membranes for ion selective detection.
  • Automatic packaging based on thermocurable and photocurable encapsulant polymers.

Device features

  • Small size, adaptable to miniaturized systems.
  • Robustness due to non-glass and solid state nature.
  • Response time up to 10 times faster than glass electrode.
  • High long-term stability.
  • High reproducibility.
  • Low impedance output signal.
  • Low cost (mass production).
  • Stores dry, no maintenance required.


  • Biomedical analysis.
  • Environmental monitoring.
  • Industrial process control

More Information

Dr. Carlos Domínguez Horna
Campus UAB
08193 Bellaterra (España)
Tel.: +93-594-77-00

Sr. Humberto Mata
D+T Microelectrónica
Campus UAB
E-08193 Bellaterra (España)
Tel.: +93-594-77-00