Researchers are developing a low-power nanomaterials-based microheater gas sensor platform. During this project, the research team will tailor the platform for realtime monitoring of hazardous gases such as hydrogen sulfide. To fully discriminate among hazardous gasses, there needs to be an understanding of gas-nanomaterial interactions and how these interactions depend on the temperature of the microheater gas sensors. Discrimination between various gases with similar chemical reactivity will require new measurement techniques and development of new nanoparticle materials with enhanced affinities for specific gases.
The low power microheater gas sensor arrays have a very small form factor, average power consumption of microwatts to a few milliwatts, and can accommodate multiple sensors on a single chip without increasing in size. Small, low power, low cost multi-gas detectors that can selectively detect various gases can have a large impact on worker safety, public health, and environmental protection. These gas sensor arrays can be wirelessly interfaced to smartphones, making the data more accessible to the individual user, and remotely accessible via wireless networks. Wide area deployment of such sensors would enable mapping of environmental pollutant and toxic gas release in both industrial and public settings.
The major goal of this project was to assess the commercial viability of a microheater-based gas sensing platform developed under the Center of Integrated Nanomechanical Systems (COINS), a UC Berkeley-headquartered NSF-funded Nanoscale Science and Engineering Center (NSEC). Researchers within COINS had developed a very low power microheater and shown its utility as a hydrogen sulfide gas sensor. Due to its very low power and small form factor, we believed it would be of use as a personal gas monitor for industrial workers in industries, such as oil and gas, paper and pulp, and sewage treatment. To assess the commercialization potential of this technology, our team was tasked with interviewing 100 people from these industries as well as people in the gas detection industry. By talking to these people, we were supposed to gain insight into the needs of the industry and determine whether our technology could alleviate a "pain point". At the end of the program, we were to determine whether we had a "Go" to form a company around this technology. After interviewing potential customers, we realized that for the most part they were very happy with their current H2S sensors and the issues they did have with them were either related to user interface issues or other issues that our technology would not address. The issues of size for H2S monitors was not an issue, since they were not actually used as a personal monitor, but mostly as a quasi-fixed monitor to test the air before performing confined entry work. Therefore, size was not an issue. The current method used for H2S detection is electrochemical sensing, which consumes very little power, so we did not have a competitive advantage there either. One pain point that our technology could address was in extreme environments (very hot or very cold and very humid or very arid), but these sectors were small. By interviewing these "customers", we did find an unexpected potential application for our low power sensing platform. We knew that flammable gas detection was currently accomplished using relatively high power, heated sensors, such as pellistors or catalytic bead sensors. However, since flammable gas is not toxic to humans, a personal monitor is not needed. Instead, fixed monitors are used to detect leaks of flammable gases. Since the monitors are fixed, we had assumed that a higher power device would not be a burden, because they could be easily connected to a wired power source. However, what we learned is that there is a significant cost burden to running power lines to fixed monitors in industrial settings. Therefore, there was an opportunity for small, low power sensor platform for battery-powered, FIXED flammable gas monitoring. While there was little opportunity for a personal gas monitor, there was an unexpected opportunity as a fixed monitoring for reasons that we would never had realized without talking to customers about their needs and how they use their gas detection equipment. Such battery-powered, fixed flammable gas monitors would be especially useful for sea-based oilrigs, which are broken down and reassembled multiple times a year. After the "customer discovery" phase of our program, we decided that we had come to a "No Go", meaning we were not ready to form a company around this technology, since it had to first be adapted to target flammable gases not hydrogen sulfide. Therefore, we went back to the lab and began testing our microheater platform as a ultra low power catalytic bead sensor. The perspective that the I-Corps program gave to the researchers was instrumental in understanding how to develop technology for commercial applications and allow them to successfully secure follow-on funding to develop the technology under the National Science Foundation’s Accelerating Innovation Research - Technology Translation program. The I-Corps program gave the PI and the graduate student invaluable insight into a methodology for assessing a technologies usefulness that is not available in "traditional" science and engineering training. Rather than look at a technology and ask "how could I put this technology to use", one should instead find true "pain points" is various industries and then ask "how might I address this pain point". It flipped the participants thinking on its head and made us realize that it is very hard to push a technology onto a problem and much easier to have the problem pull a solution out of the technology. The team is still in communication with some contacts made through the I-Corps program and are in dialog as to how to collaborate with these companies, including Honeywell, who is especially interested in our low power microheater platform. We have also published a manuscript titled "Catalytic hydrogen sensing using microheated platinum nanoparticle-loaded graphene aerogel" in Sensors and Actuators – B. This research was a direct result of the renewed focus of our research on flammable gas detection.
