A research team led by the School of Engineering of the Hong Kong University of Science and Technology (HKUST) has addressed the long-standing challenge of creating artificial olfactory sensors with arrays of diverse high-performance gas sensors. Their newly developed biomimetic olfactory chips (BOC) are able to integrate nanotube sensor arrays on nanoporous substrates with up to 10,000 individually addressable gas sensors per chip, a configuration that is similar to how olfaction works for humans and other animals.

For decades, researchers worldwide have been developing artificial olfaction and electronic noses (e-noses) with the aim of emulating the intricate mechanism of the biological olfactory system to effectively discern complex odorant mixtures. Yet, major challenges of their development lie on the difficulty of miniaturizing the system and increasing its recognition capabilities in determining the exact gas species and their concentrations within complex odorant mixtures.

To tackle these issues, the research team led by Prof. FAN Zhiyong, Chair Professor at HKUST’s Department of Electronic & Computer Engineering and Department of Chemical & Biological Engineering, used an engineered material composition gradient that allows for wide arrays of diverse sensors on one small nanostructured chip. Leveraging the power of artificial intelligence, their biomimetic olfactory chips exhibit exceptional sensitivity to various gases with excellent distinguishability for mixed gases and 24 distinct odors. With a vision to expand their olfactory chip’s applications, the team also integrated the chips with vision sensors on a robot dog, creating a combined olfactory and visual system that can accurately identify objects in blind boxes.

The development of the biomimetic olfactory chips will not only improve the existing broad applications of the artificial olfaction and e-noses systems in food, environmental, medical and industrial process control etc, but also open up new possibilities in intelligent systems, such as advanced robots and portable smart devices, for applications in security patrols and rescue operations.