Towards a truly biomimetic olfactory microsystem: an artificial olfactory mucosa

Abstract

Today, the capability of the human olfactory system is still, in many ways, superior to that of the electronic nose. Although electronic noses are often compared with their biological counterpart, they neither mimic its neural architecture nor achieve its discriminating performance. Experimental studies on the mammalian olfactory system suggest that the nasal cavity, comprising of the mucous layer and the olfactory epithelium, performs a degree of chromatographic separation of complex mixtures. Thus receptor cells distributed beneath the mucous layer provide both spatial and temporal chemosensory information. Here we report on the development of an artificial olfactory microsystem that replicates this basic structure. This contains an integrated channel to emulate the nasal cavity and coated with a polymer to mimic the partitioning mucous layer, which is positioned directly over a sensor array. Our system employs an 80 element chemoresistive microsensor array with carbon black/polymer odour-sensitive films combined with a microfluidic package fabricated by micro-stereolithography. Results show that this biomimetic system generates both spatial and temporal odorant signals, with a temporal chemical retention period of up to 170 s. Data analysis has revealed improvements in its ability to discriminate between two simple odours and a set of complex odours. We believe such emulation of the olfactory system can lead to improved odour discrimination within the field of electronic noses.

Mimicking Biological Design and Computing Principles in Artificial Olfaction

“…Motivated by this approach a microfluidic channel coated with a polymeric material was fabricated and mounted to the front end of a chemiresistive microsensor array (61). The internal coating of this ‘artificial mucosa’ allowed differential transport of odor molecules across the linear array with 16 columns of five different sensing elements each (Figure 4b).…”

Applying Convolution-Based Processing Methods To A Dual-Channel, Large Array Artificial Olfactory Mucosa

“…In order to mimic the 'nasal chromatograph' effect such as in the mammalian olfactory system [9], two retentive columns like nares but with different retentiveness were used (Figure 3). Each column was of similar size (0.38 mm × 0.25 mm × 2000 mm) and coated with a different coating.…”

Towards biological plausibility of electronic noses: A spiking neural network based approach for tea odour classification

“…This dichotomy and with the increased understanding of biological olfaction mechanisms, has led to the realization of several bio-inspired artificial olfactory systems not only at the abstraction level but also at the data processing stage [4,5]. Also, with the advent of novel bio-mimetic systems such as artificial olfactory mucosa [6][7][8] and an increase in the sensor array size it becomes challenging to be able to reduce the dimensionality while preserving relevant information in addition to computational overheads [7,8]. This calls for advanced time dependent bio-inspired computational techniques to address challenging odour discrimination problems like segmentation [8].…”

“…Recent efforts towards mimicking biological neuron type computation and information transfer has led to the development of neural networks such as the spiking neural network (SNNs) [17,18]. Researchers have used these SNNs to successfully develop bio-mimicking pattern recognition schemes for the ENs [6,9,[19][20][21][22][23][24][25][26][27][28][29]. Along these lines, we use the SNN for odour discrimination over the temporal spike codes.…”