SBIR Phase II: A Reversible, Colorimetric Hydrogen Safety Sensor Using Tailored Xerogels

This Small Business Innovation Research (SBIR) Phase II research project will optimize performance of an optical safety sensor for integration with the hydrogen economy infrastructures. Feasibility of the sensing approach was demonstrated by developing a sol-gel-titania-based indicator formulation, which showed complete reversibility, and response and recovery time of less than a minute with 4% hydrogen. Safety remains a top priority since leakage of hydrogen in air during production, storage, transfer and distribution creates an explosive atmosphere for concentrations between 4% (v/v) - the lower explosive limit (LEL) and 74.5% (v/v) - the upper explosive limit (UEL) at room temperature and pressure. Being a very small molecule, hydrogen is prone to leakage through seals and micro-cracks. The sensor will be further improved with regard to its dynamic detection range, response and recovery times, sensitivity, accuracy, resolution and reduced interference from temperature fluctuations, and atmospheric gases including humidity. Hydrogen economy is new; public acceptance of hydrogen fuel would require the integration of a reliable safety sensor. Global energy consumption is projected to increase by 50% over the next 20 years. Failure to develop alternatives to oil would heighten growing reliance on oil imports, raising the risk of political and military conflict and economic disruption. The acceptance of hydrogen by the general public as an alternative fuel requires a safety sensor for mitigating the explosion risks due to hydrogen leakage at unacceptable levels.