A Flexible Multi-Channel Platform for Versatile E-Nose and E-Tongue Operations

This paper introduces a flexible multi-channel platform designed for integrating multiple sensors, among which electronic noses (e-nose) and electronic tongues (e-tongue), targeting food quality and safety assessments. The proposed device is designed aiming for maximum portability, allowing on-site analyses, and maximum modularity, to meet user requirements. The customizable configurations allow the user to adjust the number of channels, current ranges, and voltage settings and to perform different analyses simultaneously. A variable number of sensing modules with different features can simultaneously be interfaced with the same control board, equipped with a microcontroller unit and a wireless module to both process data for on-board analyses and send it to the cloud. The modular design of the system allows for interchangeable sensing modules, offering high flexibility in sensory analysis compared to the existing portable solutions. Two custom dual-channel module boards have been designed with different operating current ranges, minimizing power consumption for extended portability, requiring only 3.16mA per channel during operations of the high-current module and 2.11mA for the low-current module. Device characterization demonstrates high linearity, with an R-squared higher than 0.999 over the entire voltage range. The channel-to-channel gain mismatch is limited to 0.26%. Spectral analysis shows 20 μVrms of equivalent noise, leading to an equivalent minimum sensor resolution of 16 noise-free bits.