SBIR Phase II: Ultrasensitive ion-sensors for wide range pressure measurement

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is enabling increased throughput and quality in semiconductor, chemical and biochemical manufacturing. The ability to monitor pressure from atmosphere to ultra-high vacuum is a critical need for these industries. This need is currently addressed by using combinations of vacuum monitoring technologies that, in many cases, require the high cost of employing multiple devices for a single job, allowing for multiple failure modes, and increasing the space constraints on the manufacturing equipment. Errors in accuracy in current systems can lead to lower production yields and failures due to exposure of fragile elements to atmospheric pressure can lead to higher maintenance costs and lower process availability. In this context, this new technology offers a substantial commercial benefit across several large-scale manufacturing industries. This technology will be further leveraged for other large-scale verticals such as mass spectrometry and radiation detection. This Small Business Innovation Research (SBIR) Phase II project will exploit ultrasensitive ion-sensing properties of low-power graphene sensors combined with voltage-controlled ion sources and resetting mechanisms for vacuum sensing. The core scientific breakthrough that underpins this technology is an ultrahigh intrinsic charge-to-current amplification mechanism inherently present in the graphene sensors. This results in measurable changes in electrical conductance caused by the attachment of trace quantities of ions on the sensors. The nonlinear nature of the charge-to-current amplification scales to higher values at lower ion-flux rates, thereby allowing greater effective sensitivity at lower pressures. In addition, combining these sensors with voltage-tunable ion sources and appropriate resetting mechanisms enables stable, long-term operation over a wide range of operating vacuum pressure. Manufacturing sensors at the chip scale allows for multi-sensor readout for improved signal and reproducible behavior, along with resilience against failure. Taken together, these technological innovations will allow the development of high-performance vacuum gauges for diverse applications. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.