Researchers develop a network of versatile, reconfigurable, damage-tolerant single-wire sensors

Researchers from the Hong Kong University of Science and Technology (HKUST) have developed sensor network design technology inspired by the human auditory system. By mimicking the human ear’s ability to distinguish sounds through tonotopy, this innovative approach to sensor networks could optimize the application of sensor networks in areas such as robotics, aviation, healthcare and industrial machines.

The team’s findings, made in collaboration with the City University of Hong Kong, were published in the journal Scientists progress in an article titled “Reconfigurable, damage-tolerant single-wire sensor array inspired by auditory tonotopy.” Dr. Long Zhihe and Mr. Lin Weikang are the first authors of this work.

Traditional sensor networks face challenges such as complex wiring, limited reconfigurability, and low damage resistance. The design developed by the HKUST team, led by Associate Professor Yang Zhengbao of the Department of Mechanical and Aerospace Engineering, addresses these challenges by assigning a unique frequency to each sensor unit and using the signal from the sensor unit to modulate the amplitude of the frequency signal, similar to the distinct frequencies processed by the hair cells of the human cochlea.

These amplitude-modulated signals of different frequencies are then superimposed onto a single conductor, and a fast Fourier transform algorithm is ultimately used to decipher the individual signals. This design allows a large number of output wires to be reduced from the conventional single-wire row-column configuration, without sacrificing functionality.

This innovative method allows the decoding system to process information from all sensor units simultaneously, which is in stark contrast to the current implementation of time-division multiplexing for decoding sensor networks.

The research team leverages a redundant design in the sensor connection network to ensure continued operation, even when parts of the array connection network are damaged. This design feature draws inspiration from the multiple synaptic connections between inner ear hair cells and neurons, providing a backup in the event one pathway fails.

This redundant design not only improves the system’s damage tolerance, but also allows for greater reconfigurability, a feature particularly useful in rapidly changing environments such as responsive robotics or adaptable wearable devices. The Lego-style modular design could also lead to maintenance cost savings because it is easier to repair than traditional multi-wire sensor networks.

The proposed sensor network technology offers a multitude of potential applications. Its flexibility and robustness make it ideally suited for integration into curved surfaces and operation in harsh environments. It can adapt to the shape and multi-modal detection requirements of the surface while providing real-time data.

In practical terms, the team demonstrated the functionality of the sensor network in two main applications: a pressure sensor network and a multimodal pressure-temperature sensor network. The latter is particularly notable for its ability to monitor critical parameters of medical prostheses, thereby improving user comfort and safety.

The team also highlighted the technology’s potential for monitoring stress distribution in aircraft wings, which could contribute to the development of safer and more fuel-efficient aircraft.

Despite its many advantages, this sensor network design encounters certain limitations. The number of sensor units in the network is limited by the operational bandwidth of the circuits, and the potential for miniaturization is limited by the size of commercially available electronic components required for each sensor unit.

Looking ahead, the HKUST team aims to further simplify the sensor network design and seek commercial partnerships to commercialize this technology.