New Sensors Safeguard Hydrogen Vehicles by Eliminating Sparking

Hydrogen as a clean, renewable alternative to fossil fuels is part of a sustainable-energy future; however, lingering concerns about flammability have limited widespread use of hydrogen as a power source for electric vehicles. Hydrogen vehicles can refuel much more quickly and go farther without refueling than today’s electric vehicles, which use battery power. But one of the final hurdles to hydrogen power is securing a safe method for detecting hydrogen.

Researchers have developed an inexpensive, spark-free, optical-based hydrogen sensor that is more sensitive — and faster — than previous models. Most commercial hydrogen sensors detect the change of an electronic signal in active materials upon interaction with hydrogen gas, which can potentially induce hydrogen gas ignition by electrical sparking. The new sensor detects the presence of hydrogen without electronics.

Hydrogen power has many more applications than powering electric vehicles and flammability mitigation technologies are critical. Robust sensors for hydrogen leak detection and concentration control are important in all stages of the hydrogen-based economy including production, distribution, storage and utilization in petroleum processing and production, fertilizer, metallurgical applications, electronics, environmental sciences, and health and safety.

The three key problems associated with hydrogen sensors are response time, sensitivity, and cost. Current mainstream technology for H₂ optical sensors requires an expensive monochromator to record a spectrum, followed by analyzing a spectral shift comparison.

The new nanosensors go from detection of hydrogen at around 100 parts-per-million to 2 parts-per-million, at a cost of a few dollars for a sensing chip. The new optical device relies on the nanofabrication of a nanosphere template covered with a palladium cobalt alloy layer. Any hydrogen present is quickly absorbed, then detected by an LED. A silicon detector records the intensity of the light transmitted.