Artificial Lateral Line Systems for Underwater Sensing

Artificial lateral line systems replicate the mechanosensory network found in fish, enabling underwater vehicles and robots to detect minute water movements, pressure gradients and vortical structures. These systems typically consist of arrays of flow or pressure sensors arranged along a flexible substrate or embedded within a canal analogue. By mimicking neuromasts and their hydrogel cupulae, artificial lateral lines provide directional and amplitude data on ambient flow, facilitating tasks such as obstacle detection, station-keeping and source localisation. Recent advances draw on microfabrication, piezoelectric materials and soft polymers to achieve high sensitivity, low power consumption and biocompatibility. Integration with signal processing and machine-learning algorithms has further enhanced robustness against noise and allowed real-time interpretation of complex flow fields. This technology holds global significance for environmental monitoring, autonomous underwater navigation and marine resource exploration, offering a low-cost, scalable alternative to traditional sonar and optical sensors in turbid or cluttered environments.

Research from Nature Portfolio

One foundational study introduced miniature all-polymer flow sensors that emulate ciliary bundles by combining polydimethylsiloxane micro-pillars of graded height with piezoelectric nanofibre tip links. Encased in a hydrogel cupula, the device achieved sub-centimetre-per-second detection thresholds and self-powered operation, paving the way for flexible, biocompatible flow sensors for underwater robots. A complementary effort developed MEMS-based artificial hydrogel neuromasts featuring an electrospun nanofibril scaffold and hyaluronic acid cupula. Matching the mechanical properties of biological neuromasts, the sensor achieved a 3.5–5-fold sensitivity enhancement and sub-micrometre-per-second flow resolution, demonstrating that faithful reproduction of cupula morphology can markedly improve performance in biomimetic flow sensing.

Artificial Lateral Line Systems for Underwater Sensing publication trend

The graph below shows the total number of articles in artificial lateral line systems for underwater sensing across all publications each year (not limited to Nature Index journals).

Technical terms

Lateral line: A distributed mechanosensory system in fish that detects water motions and pressure gradients.

Neuromast: A sensing unit within the lateral line comprising hair-cell bundles topped by a gelatinous cupula.

Cupula: A hydrogel-like structure that transmits fluid drag to embedded hair cells or sensors, enhancing sensitivity.

Piezoelectric sensor: A device that generates an electrical signal in response to mechanical deformation by flow or pressure.

MEMS (Microelectromechanical Systems): Miniature devices that integrate mechanical sensing elements with electronics on a single chip.

Biomimetic: Design and fabrication approach inspired by natural structures and functions to achieve enhanced performance.

Hydrodynamic flow: Movement of water characterised by velocity, direction and pressure; often complex near obstacles or in vortices.

References

1. A Review of Artificial Lateral Line in Sensor Fabrication and Bionic Applications for Robot Fish. Applied Bionics and Biomechanics (2016).
2. Fish-inspired self-powered microelectromechanical flow sensor with biomimetic hydrogel cupula. APL Materials (2017).
3. Nanofibril scaffold assisted MEMS artificial hydrogel neuromasts for enhanced sensitivity flow sensing. Scientific Reports (2016).
4. Head Horn Enhances Hydrodynamic Perception in Eyeless Cavefish. Advanced Science (2024).
5. Fish Lateral Line Inspired Flow Sensors and Flow-aided Control: A Review. Journal of Bionic Engineering (2021).
6. Bio-inspired all-optical artificial neuromast for 2D flow sensing. Bioinspiration & Biomimetics (2018).