The Engineering Projects

Smart Buildings Boost the Need for Intelligent Gas Sensors

The global smart building market is expected to reach approximately $33.5M by 2022, indicating a vastly growing need for safe and secure building environments. These sensors continuously monitor environments to ensure that the air quality, temperature, and ventilation in a building are accurate. They can identify scores of potential threats - including harmful gases and gas leaks. According to one recently published report, the need for more sophisticated and intelligent gas sensors in the smart building of the automation industry is critical - this is because consumers demand security where tighter governmental regulations are calling for better and safer indoor air quality.

How Gas Sensors Improve Building Safety?

Gas sensors play a vital role in building safety. They are designed to detect and monitor gas leakage and toxic gases. This is achieved through safety inspections that focus on testing air quality in different parts of the building. New health and safety regulations passed by governments across the globe mean that gas sensors boasting high sensitivity to gases are becoming an important part of safety systems.

These sensors are electronic devices with the ability to detect the existence of (and particular concentrations of) different gases in the environment. Based on the concentration of gases in the atmosphere, the sensors show the different resistance levels of various substances used in the device to check for fluctuations in output voltages. Depending on the readings obtained, we can identify the type and concentration of different gases.

What Type of Gas Sensors Are Used in Engineering?

Gas sensor technologies are used to boost engineering safety - including non-dispersed infrared sensors for carbon dioxide detection and miniaturized photo-ionized detectors for measurement.

In the past, buildings used to contain different sensors, occupying significant space. A need has therefore arisen for more compact, robust, powerful, and reasonably priced sensors that can ensure safety in different sectors - including the health, oil, gas, and automation industries.

Detecting Combustible Gases

Modern-day gas sensors can detect a wide array of gases - including combustible gases such as methane, butane, propane, hydrogen, and more. These sensors can detect the presence of toluene, ozone, nitrogen dioxide, and other gases, offering a reading in the range of 0 to 5 parts per million.

The components used in the sensors can respond to changes in physical or chemical properties. The latter is converted to electric signals by transducers; the sensors measure the concentration of different gases through analytic reactions between the sensing material and target gases. Various types of sensors exist; for example, optical gas sensors measure the amount of light scattering caused by different type of gases. The type of sensor used depends on its intended application. For instance, catalytic sensors are better and therefore preferred for combustible gas detection, while carbon nano-materials are usually chosen for environmental monitoring. These materials have different advantages as well in terms of sensitivity, cost, response time, weight, and stability.

New Chemistry for Ultra-Fine Gas Sensors

Engineering teams are constantly on the lookout for more efficient, lighter sensors capable of fulfilling more than one role. On July 1, 2020, scientists from Ruhr-University Bochum announced that they had developed a new process for zinc oxide layers that can be utilized both ways i.e. as a protective layer on plastic and for sensing the presence of toxic nitrogen gas. These layers can be laid down via atomic layer deposition, which contains chemical compounds (or precursors) that ignite when they come in direct contact with the air. The Ruhr-University Bochum team created a new manufacturing process using a non-pyrophoric zinc precursor that can be made at temperatures that are low enough for plastics to be coated. These zinc oxide layers can do many functions all in one fell swoop - including that of protecting degradable goods.

How are Ultra-Thin Zinc Oxide Layers Made?

In the manufacture of sensors for nitrogen dioxide, a fine layer of nanostructured zinc oxide is applied to a sensor substrate that is then joined to an electric component. The Ruhr-University Bochum scientists have used atomic layer deposition (ALD) to join the ultra-fine layers to the sensor substrates. ALD processes are usually used in engineering to make tiny electrical parts using ultra-thin layers. Some are just a few atomic layers thick, yet they are robust and highly efficient. For this process, specific precursors that can form such fine layers are required. Up until now, these layers were made using highly reactive, and highly pyrophoric zinc precursors via ALD.

Working in a Safer Fashion

The new method allows teams to work safely by avoiding highly ignitable compounds. It relies on very safe, low temperatures that enable the deposition of the layers onto plastic. It is therefore of great use in the production of gas sensors as well as in any industry in which goods need to be protected from oxidation through the use of plastics. The food and pharmaceutical industries are two sectors that can potentially benefit from these gas-protected plastic layers. The gas sensor market is predicted to grow exponentially every day. Continuous monitoring of gas levels is key to ensuring the health and safety of those living and working in buildings where they need to deal with toxic and sensitive gases every day. Trends dominating this product include a need for greater customization, lower-cost sensor technology, and smaller-sized sensor packages. Due to the high demand for smart buildings over the years, the desire for continuous and accurate gas measurement is increasing daily. These sensors are high in demand in different areas including the Asia Pacific Region, the Middle East, and North America. Moreover, several new chemical processes are required for the creation of ultra-thin and efficient gas sensors.

This is achieved by atomic layer deposition using precursors that require low heat and can protect the integrity of the plastic. A small amount of fine nanostructured zinc oxide is applied to a sensor substrate before connecting it with an electric component. This new intelligent gas sensor technology is used in the gas and packaging industries.