CMOS ISFET-based pH Sensor

This technology describes novel transformations of CMOS Ion-Sensitive Field Effect Transistors (ISFETs) for use as pH-sensors. In currently available alternatives of the same genre, two MOSFET-ISFET combines with different pH-stimulated electrodes ar e connected in a differential format (to yield greater accuracy) to yield the pH sensors. The attachment of the electrodes involves undesirable post-processing. In this technology, instead of modifying the electrodes, one of the MOSFET-ISFETs is slig htly modified during chip-making to yield conductance characteristics different from the other. This is connected to another unmodified MOSFET-ISFET (with the same kind of electrode attached to each) in a differential format and then calibrated. The summary of advantages is as follows:


The device and technique scores on miniaturization (higher integration) and lower power requirements as against available alternatives

Since the pH-sensitivity difference is engendered during process o post-processing of ISFETS is required to add electrodes (i.e., making of the pH sensor chips in one go).

The technique is quicker and cheaper than alternatives

The technique is scalable and the devices, mass-produce-able

The ighly favored CMOS material as against alternatives like glass. ISFET-based sensors are easier to clean, has no polarization effects from wiping or scrubbing, are durable and respond more quickly than alternatives

The device has been experimen y tested and yields good linear outputs.

Categories: General Engineering

Type of Offer: Licensing



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