17d. Laser-based ammonia slip sensor for on-road diesel-powered vehicles

Current sensors for real time measurements of ammonia in automotive exhaust are lacking in detectivity, operability, and suffer from significant cross-sensitivity with interfering exhaust species. New ammonia sensing technologies that address these shortcomings are needed to precisely control and optimize next-generation exhaust aftertreatment systems. With these high-performance ammonia sensors, exhaust aftertreatment systems can be operated more efficiently, leading to major reductions in vehicle exhaust pollution as well as an increase in fuel economy. To overcome the shortcomings of existing in-exhaust ammonia sensors, Indrio will utilize laser-absorption spectroscopy, which is a detection principle that is vastly different than existing approaches. By probing the unique molecular spectral fingerprint of ammonia, the laser-absorption spectroscopy approach is fundamentally insensitive to competing exhaust species and can achieve ammonia detectivities rivaling expensive lab-grade instruments. Additionally, Indrio will leverage its patented optical manufacturing technologies to produce sensors that rival the form-factor, durability, and cost of existing ammonia sensors. Indrio and Southwest Research Institute will construct and test a prototype LAS-based sensor instrument capable of measuring the concentration of ammonia within vehicle exhaust. Indrio will perform all of the sensor design, component manufacturing, assembly, and sub-scale testing tasks needed to assemble and validate a working sensor prototype. Southwest Research Institute will operate its advanced automotive engine exhaust testing facilities to provide a real-world test environment for assessing the performance of the Indrio-designed sensor. If successful, the sensor developed through this SBIR effort will be widely installed in vehicles equipped with next-generation exhaust aftertreatment systems, resulting in demand on the order of millions of units per year. The manpower and supply chain needed to meet this demand will have a significant positive impact on local and greater US economies. Additionally, with significantly improved ammonia sensing capabilities, vehicles will pollute less and consume less fuel, providing tangible benefits to the air quality and to vehicle operating expenses.