Team DuraFET

Competing for the Wendy Schmidt Ocean Health XPRIZE with an array of Durafet pH sensors

Bob Carlson, Honeywell, Inc.

Ken Johnson and the Chemical Sensor Lab, Monterey Bay Aquarium Research Institute

Todd Martz, Scripps Institution of Oceanography

Sea-Bird Scientific (Jim Hochstein, Dave Murphy, Tom Mitchell, Ronnie Van Dommelen, Keith Brown)

The Deep-Sea DuraFET. A pressure tolerant ISFET pH sensor

18 months of pH measured near Hawaii on profiling floats 7672, 8486 and 8514.

Sensor performance has been validated in multiple tests. Below, a comparison of sensor pH operating in situ (blue line) and spectrophotometric pH (mcp method, black dots) on samples returned by the SIO rosette (top photo) is shown. Data obtained by Dr. Yui Takeshita of SIO.

XPRIZE pH sensors

• Satlantic SeaFET


• Scripps Institution of Oceanography SeapHOx


• MBARI Deep-Sea DuraFET

Durafet References

• Built around the Honeywell Durafet Ion Sensitive Field Effect Transistor


• Read more about the Honeywell Durafet for oceanographic applications


• Durafet reveals pH variability in environments from coral reefs to Antarctica


• Other ocean Durafet references

Realtime Durafet data

• pH on deep-sea moorings


• pH on coastal moorings


• pH measurements on the L01 LOBO estuarine moorings


• pH on Apex profiling floats equipped with a 2000 m rated Deep-Sea DuraFET

Launching a LOBO mooring with 5 SeaFET and SeapHOx pH sensors to test antifouling schemes on a rare, calm day in Monterey Bay.