Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists create artificial cricket hairs

20.06.2005


Scientists have re-created one of nature’s most sensitive sound detectors – the tiny hairs found on body parts of crickets, which allow them to hear predators and make an escape before they get close enough to catch them. Published today (20th June 2005) in the Journal of Micromechanics and Microengineering, an Institute of Physics journal, this research will help scientists understand the complex physics that crickets use to perceive their surroundings and could lead to a new generation of cochlear implants, for people with severe hearing problems, in the far future.



Crickets spend most of their lives on the ground, making them vulnerable to wandering and flying predators. Species such as the wood cricket Nemobius sylvestris have developed a pair of hairy appendages at the abdominal end of their body called cerci, which are incredibly good at detecting small fluctuations in air currents – the kind that might be caused by the beating of a wasp’s wings or the jump of an attacking spider.

Each of the hairs on a cricket’s cerci is lodged in a socket, which allows them to move in a preferred direction. Airflow causes a drag force on the hair, rotating its base and firing specific neural cells, which allows the cricket to pinpoint low-frequency sound from any given direction by using the combined neural information from all the sensory hairs on the cerci.


Physicists at the University of Twente in the Netherlands have now succeeded in building artificial sensory hair systems, which they hope will enable them to unravel the underlying process and develop sensor arrays with a variety of important applications.

The Twente team, led by Gijs Krijnen and Remco Wiegerink, have shown that they can make mechanical hair sensors and are able to fabricate them in large arrays of long hairs for the first time. They have also obtained experimental results, which reveal how good these artificial cricket hairs are at sensing low-frequency sound.

The work was carried out by the MESA+ research institute at the University of Twente, as part of the European Union project CICADA (Cricket Inspired perCeption and Autonomous Decision Automata), which aims to develop a life-like perception system by studying biological concepts and trying to mimic these using the latest fabrication technologies.

Cricket hairs are incredibly energy efficient sensors, and crickets are thought to perceive flows with energies as small as or even below thermal noise levels (the background “noise” caused by the Brownian motion of particles). By evolution, the cricket has fine-tuned the hairs in order to gain as much energy from the airflow as possible.

The cricket hair canopy also shows outstanding directivity, since acoustic flow, in contrast to acoustic pressure, not only has a magnitude but also a direction. Sensitivity and directivity help crickets to perceive and escape from attacking predators, such as the wolf spider. Because of their optimised performance, cricket acoustic sensory hairs are very interesting structures to bio-mimic in man-made acoustic sensors.

The Twente team built a mechanical array with up to a few hundred artificial hairs using technologies often referred to as MEMS technology. The sensors are made by depositing and structuring various thin layers of electrically insulating and conducting materials, creating structured electrodes on a suspended membrane. The structured electrodes form two capacitors with the underlying substrate.

Long hairs, made of a photo-structurable polymer (SU-8), are put on top of the membranes. Airflow causes drag-forces on the hairs and so the membranes rotate, leading to a change in capacitance value of the capacitors.

Marcel Dijkstra, a member of the Twente team, said: "These sensors are the first step towards a variety of exciting applications as well as further scientific exploration. Their small size and low energy consumption make them excellent for application in large sensor networks, whereas there mechanical nature allows for mechanical filtering and parametric amplification. We could use them to visualise airflow on surfaces, such as an aircraft fuselage."

In a more advanced stage, the structures may form a stepping-stone towards the fabrication of hairs operating in fluids, such as found in the inner ears of mammals.

The team are now producing newer generations of hairs, which they expect to deliver sensitivities at least one order of magnitude better than what has been presented in the paper.

David Reid | alfa
Further information:
http://www.iop.org

More articles from Physics and Astronomy:

nachricht A tale of two pulsars' tails: Plumes offer geometry lessons to astronomers
18.01.2017 | Penn State

nachricht Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Explaining how 2-D materials break at the atomic level

18.01.2017 | Materials Sciences

Data analysis optimizes cyber-physical systems in telecommunications and building automation

18.01.2017 | Information Technology

Reducing household waste with less energy

18.01.2017 | Ecology, The Environment and Conservation

VideoLinks
B2B-VideoLinks
More VideoLinks >>>