在蝴蝶的翅膀上發現的光子納米結構激發了澳大利亞研究人員的靈感，他們發明了一種新型的、高精確的氫氣測量傳感器。該裝置由墨爾本理工大學的Yilas Sabri和Ahmad Kandjani領導的團隊製造。該傳感器可在氫燃料的安全工業存儲中發揮作用，也可能引導非侵入性醫療診斷新技術的發展。
作為一種有前景的可再生能源，越來越多的氫氣被儲存在世界各地的大型設施中。由於這種氣體極易燃燒，因此需要高度精確的傳感器，能夠檢測出洩漏到空氣中的哪怕是最微小的氫痕跡。當今市售的傳感器可測量金屬氧化物層與氫相互作用時電阻的變化。然而，這些設備需要超過150°C的溫度才能運行，並且還對其他類型的氣體很敏感，這限制了它們在工業應用中的潛力。
Sabri和Kandjani的團隊在研究中採用了更為複雜的方法。通過光來輔助檢測傳感器中的氫氣而不是熱量。他們的設計使用光子晶體，但也可以出現在自然界中的光學納米結構。在這種情況下，研究團隊的靈感來自一些蝴蝶的翅膀-蝴蝶有序的微小顛簸圖案，使它們的翅膀非常善於吸收光線。為了模仿這種結構，研究人員製作了一個空心二氧化鈦納米球晶格，並將其沉積到電子晶片上。然後，他們在設備上塗覆了鈦鈀複合材料以增強其靈敏度。
爆炸報警
當被光激活時，該傳感器的表面使氫氣與氧氣反應生成水。水的存在會改變傳感器的電阻，從而精確測量空氣中的氫含量。該傳感器可以測量濃度在10- 40000 ppm範圍內。因此，當氣體濃度高到足以產生爆炸風險時，它會發出警報。該裝置可以區分氫氣和其他氣體，其選擇性超過93％。
該傳感器採用既定的製造工藝製造，因此該團隊充滿信心，可以輕鬆擴大生產規模，以廣泛使用-包括氫燃料電池。此外，傳感器檢測低水平氫的能力使其適合於醫療應用。通過檢測患者呼吸中胃腸道疾病產生的氣體，臨床醫生可以更容易地進行無創診斷和監測程序。
原文閱讀：
Photonic nanostructures found on the wings of some butterflies have inspired researchers in Australia to create a new and highly accurate sensor for measuring hydrogengas.
The device operates at room temperature and was made by a team led by Yilas Sabri and Ahmad Kandjani at RMIT University in Melbourne. The sensor could play a role in the safe industrial storage of hydrogen fuel and the research could also lead to the development of new techniques for non-invasive medical diagnoses.
As a promising source of renewable energy, increasing amounts of hydrogen gas are now being stored at large facilities around the world. Because of the extreme flammability of this gas, there is a need for highly accurate sensors that can detect even the smallest traces of hydrogen that has leaked into the air.
Today’s commercially available sensors measure changes in electrical resistance in metal-oxide layers as they interact with hydrogen. However, these devices require temperatures of over 150 °C to operate and are also sensitive to other types of gas – limiting their potential for industrial applications.
Sabri and Kandjani’s team took a more sophisticated approach in their study; where instead of heat, hydrogen detection in their sensors is assisted by light.
Their design employs photonic crystals: optical nanostructures that can be manufactured, but also appear in nature. In this case, the team was inspired by the wings of some butterflies – which have orderly patterns of tiny bumps that make the wings extremely good at absorbing light.
To mimic this structure, the researchers fabricated a lattice of hollow titanium dioxide nanospheres, which they deposited onto an electronic chip. They then coated the device with a titanium palladium composite to enhance its sensitivity.
Explosion alarm
When activated by light, the surface of this sensor reacts hydrogen gas with oxygen to create water. The presence of water changes the sensor’s electrical resistance, providing a precise measure of the amount of hydrogen in the air.
Operating at room temperature, the sensor can measure concentrations in the 10-40,000 parts-per-million range. It can therefore sound the alarm when the concentration of the gas is high enough to be an explosion risk. The device can discriminate between hydrogen and other gases with a selectivity that exceeds 93%.
The sensor was made using established fabrication processes so the team is confident that production could easily be scaled up for widespread using – including in hydrogen fuel cells.
Furthermore, the ability of the sensors to detect low levels of hydrogen make them suitable for medical applications. By detecting the gas produced by gastrointestinal disorders in a patients』 breath, clinicians could carry out non-invasive diagnoses and monitoring procedures far more easily.