Insect Bits & Bytes (May 2013)

This month’s topics:

Compound eye-inspired camera

Robotic Flyer

Water-repellent, self-cleaning cicada wings

Thin film interface inspired by moth eyes

Ants tunneling, falling and catching themselves

Sound perception in moths

Jumping Robots

Some of you might be thinking that the topic of this blog is rather narrow: “How can she possibly sustain this blog because she is going to run out of topics at some point…soon”.

Or is that just the voice in my own head talking?

I only have to remind myself that I have chosen a taxon, the Insecta, which is extremely diverse and that new species are being discovered and described every day, so it is very likely that I am going to be occupied for a while. Insects have adapted to many different environments, often through very novel and varied (compared to mammals) adaptations. Inspiration for innovation is bound to be found in common insects, but also in the obscure. And if I adopt the often ignored non-insect arthropods such as ticks, mites, spiders, etc., then I will be set until retirement. At the same time imaging and manufacturing techniques are making the small visible and producible so advances in engineering are helping me stay off the streets too.

In this inaugural “Insect Bits & Bytes” post I highlight some of the research I came across on Twitter (#biomimicry or #bioinspiration) during the month of May. These studies all involve new technologies that were inspired by insects or basic discoveries about insect biology that could lead to new innovations.

I have compiled a list of links to this work, as well as to coverage of the research by some of my favorite science writers. I hope to do the same at the end of every month.

Compound eye-inspired camera

The biggest insect-inspired technology story came from the University of Illinois at Urbana-Champaign (my home institution). John Roger’s material science lab was inspired by the insect eye to develop a new digital camera.

RogersBeeEye

New digital cameras exploit large arrays of tiny focusing lenses and miniaturized detectors in hemispherical layouts, just like eyes found in arthropods. Photo credit: John A. Rogers, UIUC

These hemispherical cameras depend on the manufacturing technique that has been perfected in the Roger’s lab – manufacturing flexible electronics.

Engineers have tried to manufacture compound eyes before. In 2006 UC Berkeley’s Luke Lee fabricated an artificial compound eye in his lab. He created thousands of closely packed light-guiding channels leading to pin-head-sized polymer resin domes and then topping each dome with its own lens. Each individual unit is very similar to an insect’s ommatidium (the individual unit of the compound eye). The fabrication method itself was based on the developmental stages of the insect, and resulted in a 3D artificial compound eye that is similar in size, shape and structure to the insect’s compound eye.

In my opinion, because of how the “eye” is manufactured and functions, Lee’s artificial eye is closer to its model than this new bioinspired eye from the Roger’s lab. Time will tell if, by adding engineering shortcuts in manufacturing, and by using materials that work better with how we currently use electronics, a more useful camera or sensor is created.

Reference: Song, Xie, Malyarchuk, Xiao, Jung, Choi, Liu, Park, Lu, Kim, Crozier, Huang & Rogers. 2013. Digital cameras with designs inspired by the arthropod eye. Nature http://dx.doi.org/10.1038/nature12083

Coverage:

Robotic Flyer

Over the years it has been exciting to see how small engineers can make flying robots. Research by people like Michael Dickinson on insect aerodynamics have helped engineers such as Ron Fearing and Rob Wood to develop microrobots that can fly. This past month we learned that the Wood lab at Harvard’s Wyss Institute has now manufactured a controllable robot, the size of an insect, that can fly. (Note: the manufacturing process for these types of robots is really cool too.)

One of the major remaining challenges, before microrobots will be used on a grand scale, is to get them enough power to walk, run, swim and/or fly for an extended time (note the tether in all the flying minirobot pictures and videos). There is just not enough room on a small robot to incorporate conventional batteries, or even smaller lightweight battery sources like a coins cell or solar panels. Future advances may involve biological motors as power sources. Maybe we can even learn more about basic insect flight energetics (a very interesting topic) and incorporate what we learn about basic insect physiology into microrobots.

Reference: Ma, K. Y., Chirarattananon, P., Fuller, S. B. & Wood, R. J. 2013. Controlled flight of a biologically inspired, insect-scale robot. Science. http://dx.doi.org/10.1126/science.1231806

Coverage:

Water-repellent, self-cleaning cicada wings

Cicadas all over the news these days. The East Coast of the US is in the midst of the 17-year periodical cicada emergence. This year cicadas are apparently also of great interest to those studying biological materials at the nanoscale. Earlier this year it was reported that nanopillars on clanger cicada wings can tear bacterial membranes apart. One can think of interesting applications for engineered materials that incorporate similar structures.

This month another study showed that cicada wings are also extremely hydrophobic; droplets pretty much jump off of the surface. The wings are thus self-cleaning. Again, one can think of multiple applications for an engineered hydrophobic material based on the cicada wing. Then again, there are many other examples of biological materials that have similar characteristics: lotus leaf, Namib beetle, etc. One interesting idea that Charles Choi brought up in his article (link below) is the use of cicada-wing technology in power plants. Jumping droplets would help dissipate heat.

Reference: Wisdom, K. M., J. A. Watson, X. Qu, F. Liu, G. S. Watson & C-H. Chen. 2013. Self-cleaning of superhydrophobic surfaces by self-propelled jumping condensate. Proceedings of the National Academy of Sciences of the USA. http://dx.doi.org/10.1073/pnas.1210770110

Coverage:

The coverage of this story was, and still is, plagued by a #TaxonomyFail (pointed out to me by @BrianTCutting). Most of the coverage associated with this story showed a picture of a wet fly, sometimes a wet fly that was upside down. Soon I hope to add a picture to this post of a wet Brood II cicada. Stay tuned.

Thin film interface inspired by moth eyes

The insect eyes have it, again.

Moth eyes were the inspiration for a new multilayered material which may find application in optoelectronic devices such as solar cells. For at least 40 years we have known how nature solves the problem of light reflection. We only now have the imaging and manufacturing capabilities that will enable us to engineer and produce materials that mimic the most effective nanostructures.

Moths are generally nocturnal and any light the eye can “harvest” is a plus, reflection of light needs to be minimized.

motheye

Moth eyes reflect very little incident light. (Image by Daniel Meyer)

The “moth eye” principle was first described in 1973 by Clapham and Hutley. Their electronmicrographs showed that the surface of corneal lenses of moths are covered with conical nanostructures and it was proposed that these structures suppressed interference (reflection).

Over the past decade nanostructured materials mimicking the moth eye have been manufactured through techniques such as ion-beam etching, but application was limited because the material could only be manufactured at a small scale. Recently researchers at North Carolina State University were able to manufacture interfacial nanostructures protruding from a silicon layer into a overlaying thin film and thus eliminated interference effects. It remains to be seen if the manufacturing technique proposed in this recent work can be scaled up to produce consistent nanostructures at a reasonable cost.

Reference: Yang, Q., X. A. Zhang, A. Bagal, W. Guo & C-H Chang. 2013. Antireflection effects at nanostructured material interfaces and the suppression of thin-film interference. Nanotechnology http://dx.doi.org/10.1088/0957-4484/24/23/235202

Coverage:

Ants tunneling, falling and catching themselves

Physicists and biologists worked together to explain how fire ants tunnel through the ground. The types of descriptions of locomotion will help engineers build more useful robots.

Obviously legs are important for locomotion on land, however, functional feet may not be just the distal end of a leg (cockroach). Also, appendages such as tails, are essential for dynamically stable locomotion (gecko). These types of biomechanical principles have already been incorporated into robots. Now a recent study from Georgia Tech shows that additional appendages, antennae, do not just serve as chemical or mechanical sensors. When falling the antennae help the ant grab onto the tunnel wall. Civil engineers might also learn from this biological example since ants build tunnels close in diameter to their own body length, no matter what the substrate, so that all legs and antennae can help get a grip when falling.

Reference: Gravish, N., D. Monaenkova, M. A. D. Goodisman & D. I. Goldman. 2013. Climbing, falling and jamming during ant locomotion in confined environments. Proceedings of the National Academy of Sciences. http://dx.doi.org/10.1073/pnas.1302428110

Coverage:

Sound perception in moths

Turns out that the animal with the best hearing is the greater wax moth (one of the many scourges of bee keepers). Moths have a tympanum on either side of the abdomen. Each tympanum is innervated by just two sensory receptors. These receptors start firing at the slightest displacement of the “ear drum”.  Turns out that the greater wax moth can sense displacement caused by frequencies up to 300 kHz. In addition, this type of auditory system works at a wide range: from 20 kHz up to 300 kHz.  Engineers are keen on building a mechanoreceptor as sensitive to ultrasound as this, and with materials and structure as “basic” as a moth’s ear.

Interestingly ultrasonic sensors are preferred over photoelectric sensors in certain situations – now bioinspired technologies based on the moth eye (see above) and the moth ear may blur those distinctions.

Reference: Moir, H. M., Jackson, J. C. & Windmill, J. F. C. (2013) Biology Letters. http://dx.doi.org/10.1098/rsbl.2013.0241

Coverage:

An illustration from British Entomology by John Curtis. Lepidoptera: Galleria mellonella

An illustration from British Entomology by John Curtis. Lepidoptera: Galleria mellonella

Jumping Robots

Also, everyone’s favorite feisty insect-inspired robot, Rhex, learned to jump.

Reference: Johnson, A. M. & D. E. Koditschek. 2013. Toward a vocabulary of legged leaping. Proceedings of the 2013 IEEE Intl. Conference on Robotics and Automation. http://kodlab.seas.upenn.edu/Aaron/ICRA2013

Coverage:

Miscellaneous

Not sure if this is biomimicry or bioinspiration, but it involves insects and it is cool:

It was a insect-spirational month! Let me know if I missed anything.

I wonder what June will bring.

One thought on “Insect Bits & Bytes (May 2013)

  1. Pingback: Insect Bits & Bytes (June 2013) |

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