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 Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory

nachricht SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

How Plants Form Their Sugar Transport Routes

28.04.2017 | Life Sciences

Protein 'spy' gains new abilities

28.04.2017 | Life Sciences

Researchers unravel the social network of immune cells

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>