European team develops lightweight gas sensors to rescue trapped people

[ China Instrument Network Instrument R&D ] At present, after disasters such as earthquakes or explosions, there are many ways for search and rescue teams to find survivors. According to reports, recently, research teams from Austria, Switzerland, and Cyprus have added a powerful new technology to search and rescue. This technology can only use economic sensors to help search and rescue teams find trapped people in the rubble.

The experimental device is shown in the figure: (a) The chemicals released by the skin and breathing of trapped volunteers accumulate in a certain volume of room. (b) The sensor array consists of three chemical sensors (MoO3-doped silicon, WO3-doped silicon, and ZnO-doped titanium) that detect ammonia, acetone, and isoprene, respectively, and two commercial sensors that detect humidity and carbon dioxide. . Simultaneous use of SRI-TOF-MS measurement method for cross-validation. (c) Photograph of appearance of the sensor. (d) The sensor elements are formed from porous semiconductor films that are directly formed by flame deposition to form an aggregated/polymeric metal oxide. (e) Scanning electron microscope top view with titanium-doped ZnO as an example.

The sensor is lightweight and portable, allowing it to be carried by first searchers (eg search dogs) and easily mounted on drones. Therefore, it can find survivors in the most precious period after the disaster, which is of decisive significance to the survival of survivors.

Sotiris Pratsinis, professor of process engineering at ETH Zurich, Switzerland, described to us: “After the earthquake, many victims were trapped under collapsed buildings and were in desperate need of rapid assistance because in the first few hours, The survival rate will decline sharply over time.At present, search and rescue dogs are an indispensable and important helper for urban search and rescue because they have the unique ability to sniff out trapped humans from the rubble.However, the scope of search and rescue dogs Physical strength is limited, and they are very sensitive to stress. Therefore, we have developed a hand-sized, inexpensive sensor array that can detect survivors by smelling the chemical characteristics of humans."

The small device introduced by the team consists of five sensors. Two of them are sensors that detect humidity and carbon dioxide and can be purchased directly from the market. The other three sensors need to be customized to detect the respiratory and skin release chemicals such as acetone, ammonia, and isoprene, even if only in trace, trace-level concentrations. At present, the equipment used in search and rescue missions is heavy and expensive. If the concentration of chemical substances is not high enough, the signal will be lost. In contrast, newly developed small-scale equipment sensors are more practical.

Pratsinis continues to add: “So far we have tested sensors in simulated tests of trapped humans. During the test, volunteers were confined in a tightly sealed room to accumulate their breath and skin. Released chemicals.These sensors quickly detect the presence of humans by inducing trace amounts of chemicals (only 3 parts per billion), and the sensor's performance has reached an unprecedented level of portable detectors.The next step is planned with the After the 'like environment conditions, the sensor array is field tested.'

The results of this project have been published in the American Chemical Society journal Analytical Chemistry and entitled "Sensing with a Sensor Array."

(Original title: European team has developed a lightweight gas sensor to sniff out survivors in the disaster area for the first time)