Literature review

What is biomimicry?Biomimicry is an approach to innovation that seeks sustainable solutions to human challenges by emulating nature’s time-tested patterns and strategies. It becoming a stronger influence on engineering design and the process of utilising nature's ideas and adapting them for human use is becoming increasingly common practice, nowadays.

Any animal, plant or any creature on Earth can be a potential candidate in biomimicry industry. Same goes to houseflies. Can you think of any idea that what unique features present in houseflies can be utilised and applied for biomimetic purposes?

Actually, houseflies do have some contributions in biomimicry industry. Now, I would like to share with you guys about some example of innovations which inspired by houseflies.

1) Flying robot

Flying robot

A housefly size flying robot that mimic the biological features of flies (flying and hovering) had been created with the weight 80 mg. The robot’s wings are consists of thin polyester films reinforced with carbon fibre ribs and its ‘muscles’ are made from piezoelectric crystals, which shrink or stretch depending on the voltage applied to them. The multi-layes of ultrathin material allow the wings to flap approximately 120 times per second (similar to a housefly's flapping rate). With such a tiny scale, any airflow changes will impact the flight dynamaics of the robot. The control system has to react faster to remain stable.

The researches claim that the potential applications of the tiny flying robot are searching and rescue missions, environment monitoring and crop pollination.

The prototype still has to tether by a very thin power cable because the tiny body can't carry its own power source yet (there is no batteries that are tiny enough to be mounted on the robot’s body). However, the researchers are being optimistic and believe that the battery issue can be overcame within 10 years.

The tiny flying robot, "RoboBee"

"RoboBee" structure

Feel free to watch the video to know more about this amazing robotic fly!
http://news.harvard.edu/gazette/story/2013/05/robotic-insects-make-first-controlled-flight/

http://www.huffingtonpost.com/2013/05/03/robot-fly-insect-flight-wings_n_3207829.html


References:

Cohen, R. (2013). Robot Fly Mimics Insect Flight, Hovers With Ultrathin Wings (VIDEO). Retrieved May 24, 2016, from http://www.huffingtonpost.com/2013/05/03/robot-fly-insect-flight-wings_n_3207829.html

Perry, C. (2013). Robotic insects make first controlled flight | Harvard Gazette. Retrieved May 24, 2016, from http://news.harvard.edu/gazette/story/2013/05/robotic-insects-make-first-controlled-flight/


2) Anti-fogging material

Hexagonal structures provide anti-fogging property

This idea is inspired by flies' eyes. The common green housefly (bottle fly) can see clearly in dusty and wet environments without fogging up.

Fogging takes place when moisture drops of > 190 nano-metres in diameter form on surfaces, scattering light and making the surface hard to see through. In a humid environment, it was found that the condensation occurred only on its body and not the compound eyes. The eye is composed of thousands of repeating small hexagonal shapes, each with a diameter of the order of 20 micro-metres. And within each of those hexagons there were still more hexagonal shapes with diameters of approximately 100 nano-metres.

                                                   Condensation not occurs on fly's eyes 

Scanning electron microscope image of the compound eye of a fly

The researchers proposed that the close packed, well-ordered and hierarchical hexagonal nanostructures are one of the factors of the superhydrophobicity of the green bottle fly eyes. Superhydrophobic means that water can't wet the material and this can be used for anti-fogging, anti-freezing, anti-corrosive and self-cleaning.

Zinc nanoparticles have been assembled into hexagonal structures (mimic the flies' eyes) and the result showed it was similarly superhydrophobic to the flies' eyes. This finding allows the development of anti-freezing-fog materials for applications in some extreme environments, as well as the coating on the windows of cars, airplanes and buildings in the future.

*Freezing fog occurs when ice layer is formed due to water vapour is super-cooled. This phenomena can destruct the electrical and telecommunication networks, and reduce the lift force that keeps aeroplanes in the air.

References:

Sun, Z., Liao, T., Liu, K., Jiang, L., Kim, J. H., & Dou, S. X. (2014). Fly-eye inspired superhydrophobic anti-fogging inorganic nanostructures. Small (Weinheim an Der Bergstrasse, Germany), 10(15), 3001–6. http://doi.org/10.1002/smll.201400516

Salleh, A. (2014, May 27). “Fly-eyes” could reduce glass fogging. Retrieved from http://www.abc.net.au/science/articles/2014/05/27/4001730.htm

Fly eyes inspire anti-fogging materials discovery. (2014). Retrieved May 24, 2016, from http://media.uow.edu.au/news/UOW172664.html

3) Multifaceted camera, "bug eye" camera

As mentioned earlier, a pair of compound eyes is one of the special features which allow housefly to see a wide field (up to 180 degree). Researchers have been inspired to build a multifaceted camera which consists of 180 lenses and each connected to an individual photodetector. The array was built onto a flexible rubber mat which was then curved into a hemispherical shape. The input from all the lenses is combined into a solitary image. The whole thing (lenses and electronics) is only one centimeter in diameter.

Currently, the prototype has only few pixels which give low resolution of image but it displays an immense depth of field and a very wide-angle view that avoids the distortion seen in standard camera lenses. The mechanical bug eye consists of 180 lenses which is about the same number in the eyes in fire ants and bark beetles, that don’t have great vision. One of the researchers Dr Xiao, claimed there are 28,000 small eyes in the compound eye of the fly so they are now working hard to increase the number of lenses. Dr Xiao also mentioned that this invention can be used in surveillance cameras one day as one device could see 180 degrees and two device provide you the whole field of view. Other than surveillance purpose, it could be used as endoscopic investigations of the human body.

"Bug eye"

References:

Borst, A., & Plett, J. (2013). Optical devices: Seeing the world through an insect’s eyes. Nature, 497(7447), 47–8. http://doi.org/10.1038/497047a

Scientists make “bug-eye” camera - BBC News. (2013). Retrieved May 24, 2016, from http://www.bbc.com/news/science-environment-22372442

4) Food quality control sensors

Houseflies have extremely strong olfactory system which allow them to search food efficiently. They particular sensitive to chemical odor releasing by rotting meat. A pair of antenna that located on the head of houseflies is an important sense organ which often covered with olfactory receptors that can detect odor molecules in the air. Thus, it is important in housefly for sense of smell.

Antenna located on fly's head (1)

Antenna located on fly's head (2)

An idea has been proposed that the application of knowledge of houseflies's olfactory system in food processing industry could be done. It can be applied in food quality control sensors to optimise the
quality of food in the future.

References:

Olfactory system detects decomposition: house fly. (n.d.). Retrieved May 24, 2016, from http://www.asknature.org/strategy/47426a740b999570674796a7f33e5f6c

5) Composite film

Insect cuticle is a composite material that composed of layers of chitin, a polysaccharide polymer, and protein which organized in a laminar, plywood-like structure. It can be found in the rigid exoskeleton insects such as houseflies. It is light weight thus can provide protection to the insect without disturb its flight and it is thin that allows flexibility. The cuticle can deflect external physical and chemical strains without damaging the insect's internal organs, while providing structural support for the insect's wings and muscles.

Insect cuticle (1)

Insect cuticle (2)

People invented a film that mimic the material that made up of insect cuticle. The clear film is biocompatible, biodegradable, and micromoldable. In addition, it is twice as strong as nylon or polylactic acid (PLA), while exhibiting the strength of an aluminum alloy at half its weight. The material could be used to replace plastic materials such as bags, bottles, diapers, packing materials and etc. It also has significant role in medical industry because of its biocompatibility and biodegradability.

"Shrilk" that mimics insect exoskeleton

References:

Shrilk composite film. (n.d.). Retrieved May 24, 2016, from http://www.asknature.org/product/a3611833427a21371e893408951e9de7

Thryf, A. R. (2012). Design News - News - “Shrilk” Mimics Insect Exoskeleton. Retrieved May 24, 2016, from http://www.designnews.com/document.asp?doc_id=237263