Jump! Go Ahead, Jump, Little Springtail.

Jump! Go Ahead, Jump, Little Springtail.

And here it is. Behold the best blog-banner ever – created by Nils Cordes*! 

Of course, the premiere of such a great banner also requires a blog post that explains it. So let me try.

The animal featured in this blog’s banner is a springtail from the hexapod lineage Collembola. Collembola are not insects but entomologists are an inclusive bunch so we gladly incorporate spiders and entognathous creatures into our studies and teachings.

Springtails are very likely the most abundant arthropods on earth. They occur in the soil (different species at different depths), in leaf litter, moss, under logs, etc. One of the most distinguishing features, if you can consider anything on an animal that is only 0.12 to 17 mm long distinguishing, is the forked furca at the posterior end of the animal. The furca is present in a lot of species, but not all. Those that live deeper in the soil usually lack the structure because they do not need it since its main function is for jumping.

CollembolaBoth

Generalized “elongate” (top) and “globular” (bottom) Collembola. Furca (springing mechanism) in red – the springtail at the top has the mechanism partly retracted and the springtail in the bottom picture has the furca extended. (Marianne Alleyne)

Collembola species can have varying body shapes, but generally there are those with elongated bodies and those with more globular bodies. Collembola can walk, run and climb, but the locomotory specialty that they are best known for (and which seems to be rather ancestral) is jumping.

Globular Springtail Dicyrtomina saundersi. Body length = 1.7mm. Picture by Lord V. Used with permission.

Globular springtail Dicyrtomina saundersi. Body length = 1.7mm. Picture by Lord V. (Used with permission.)

Picture by Lord V. Used with permission.

Elongate springtail. Body length = 2.3 mm. Picture by Lord V. (Used with permission.)

This excellent picture by Lord V is of a picture walking over a glass slide. Clearly visible is the forked furca that can prope the springtail into the air.

This excellent picture is of a springtail’s underbelly. The picture was taken by Lord V as a springtail walked over a glass slide. Clearly visible is the forked furca that can propel the animal into the air. (Used with permission.)

Collembola can jump multiple times in a row, those with globular bodies and more advanced tracheal systems more often (1). In general, springtails tire easily so that jumping is usually only used as an escape mechanism. The jump can take the animal in any direction. Since the furca is located at the extremity of the body, directly beneath the center of gravity, the dynamics of the jump cause the body to rotate head over end. Some Collembola species can jump very high, others take a shallower trajectory but land far away from point of takeoff.

This jumping escape response is quite successful but it does require modifications of the entire body plan. The cuticle, the (hydrostatic) endoskeleton, tendons, and muscles all work together to manipulate the body in such a way that the propulsion is optimal.  How exactly this happens is not very well understood, yet this system holds inspirational lessons for passively compliant locomotory structures.

At rest the furca is held within a ventral groove of the abdomen. At the time of the jump the furca moves from this resting (retracted) position to the extended position. Based on morphological and kinematic observations (there is no direct experimental evidence) it appears that as the furca moves it compresses a “spring”. After it passes a critical point of extension the spring releases all the energy, which in turn causes the springing organ to snap out at high speed. If this happens as the springing organ hits a substrate a force is created that propels the animal upward.

The springing mechanism of a generalized springtail; partially retracted (left) and extended (right).

The springing mechanism of a generalized springtail; partially retracted (left) and extended (right). (Marianne Alleyne)

What exactly comprises this “spring” is not clear. Earliest experiments done by Manton (2) in the early 1970s concluded that to evert the springing organ the body’s hydraulics (pressure on the fluid that makes up most of inside of the body = hemocoel) was important. However, later in the 1970s, Christian (3) concluded that direct muscle action, and not necessarily hydraulics, was the main force inducer. In the 1990s, when high-speed photography had advanced greatly, Brackenbury and Hunt (4) concluded from their experiments that hydraulic forces created by pressurizing the hemocoel increases tension on abdominal sclerites (the exoskeletal plates) that results in a click mechanism that propels the animal into the air. All these studies do agree that elastic elements within the base of the springing organ and within the exoskeleton, as well as the body as whole, are important too. To what extent is not known.

Click mechanism model of the furca. The furca, at rest, is retracted into an abdominal ventral groove. A pair of "basal rods" (springs) are embedded in ventral and lateral parts of the abdominal sclerites 4 & 5, these springs also attach to the apex of the furca. The spring/click mechanism gets help from muscle and active dorsiflexion of the body, which both help release to spring organ from the groove)

Click mechanism model of the furca (red) and distal end of abdomen. The furca, at rest, is retracted into an abdominal ventral groove. A pair of “basal rods” (springs, in blue) are embedded in ventral and lateral parts of the abdominal sclerites 4 & 5, these springs also attach to the apex of the furca. The spring/click mechanism gets help from muscle and active dorsiflexion of the body (in orange), to release the spring organ from the groove. After the furca passes a critical point of extension the spring releases all the energy. (Drawing by Marianne Alleyne based on Brackenbury & Hunt, 1993)

Imagine a beam or a chopstick that’s flexible transversally but somewhat stiff longitudinally. If you compress it, it doesn’t change…up to a point. Then it ‘snaps’ out and buckles. You get a rapid displacement as all the strain energy is released. The exoskeleton of the springtail does a similar thing. It stores the strain energy and then goes through a snap-through buckling phenomenon to produce large strain motion which is then amplified by the tail and presto…springtail in motion.

Many insects, and other animals, use musculoskeletal springs that are incorporated into the complete body plan.  These springs help achieve a high rate of acceleration, or a further jumping distance, and help save metabolic energy. Based on these findings compliant structures and materials have been incorporated into bioinspired legged robots (5). Compliant legged robots achieve a few important things: increased energy efficiency, increased speed, ability to avoid obstacles (in case of jumping robots), and the ability to use more simplified controls to enable enhanced gait control and shock absorption. Springs in bioinspired robots have used elements such as airsprings (e.g. compressed air) and compliant materials, but improvement is still possible. Airsprings, for instance, are not very efficient because they end up converting much of the energy they store into heat. In addition, some of the compliant materials are better than others. Rubbery materials, like elastomers, tend to have a fair bit of viscosity in them and so some (maybe lots) of the energy that it stores is lost to heat as well. For high efficiency, most robotic-type systems currently use mechanical springs (i.e. metals). Bioinspired robots also incorporate series elastic actuators that have linear springs intentionally placed in series between the motor and actuator output, which results in the actuator being bulky.

The variety of jumping mechanisms among insects is great (think: click beetle, flea, grasshoppers, treehoppers, etc.). The intriguing aspect of the jumping mechanism in springtails is that it operates so efficiently at a very small scale, much smaller than any bioinspired robot that has been developed. In the future we will be able to manufacture almost microscopic devices incorporating different characteristics into small structures using “springs” and compliant materials.

Maybe we can incorporate locomotory mechanisms that propel the object, using very little energy. Inspiration for what materials to use and how to construct the object can be found through further study of the springtail’s click mechanism. Somewhat surprisingly not much research has been published on this system since the 1990s. Yet with help from today’s high-speed cameras and microscopy techniques we should be better able to understand how the springtail propels itself. Advanced computer aided engineering (CAE) tools, like finite element analysis (FEA), could be used to augment the visual data and elicit some fundamental internal characteristics that are not visibly detectable.

By researching this topic I thought of a few applications for technologies based on the Collembola’s spring mechanisms. Click mechanisms at the scale of a springtail’s springing mechanism could possibly aid stent design or inspire development of other deployable structures that snap open or closed based on certain environmental conditions. Maybe small springing mechanisms can be incorporated in groups and serve as strain sensors on bigger structures. And who wouldn’t welcome millimeter-sized robots that can perform in a futuristic “flea circus”?

PLEASE LEAVE A COMMENT (OR CONTACT ME VIA TWITTER @COTESIA1) IF YOU HAVE ANY NOVEL IDEAS FOR A SPRINGTAIL INSPIRED JUMPING MECHANISM. JUST IMAGINE.

REFERENCES:

(1) B. Ruhfus and D. Zinkler, Investigations on the sources utilized for the energy supply fueling the jump of springtails, Journal of Insect Physiology, Volume 41, Issue 4, April 1995, Pages 297-301, ISSN 0022-1910, 10.1016/0022-1910(94)00122-W.

(2) S. M. Manton. The Arthropoda: Habits, functional morphology, and evolution. Clarendon Press, Oxford, 1977. ISBN: 019857391X

(3) E. Christian. The jump of the springtails. Naturwissenschaften, Volume 65, Issue 9, 1978, Pages 495-496, 10.1007/BF00702849

(4) J. Brackenbury and H. Hunt. Jumping in springtails: mechanism and dynamics. Journal of Zoology, Volume 229, Issue 2, 1993, Pages 217-236, ISSN 1469-7998, 10.1111/j.1469-7998.1993.tb02632.x

(5) Z. Zhou and S. Bi. A survey of bio-inspired compliant legged robot designs. Bioinspiration and Biomimetics,Volume 7, Issue 4, 2012, 20 pages 10.1088/1748-3182/7/4/041001

SPRINGTAIL RESOURCES:

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*My friends can attest to the fact that I have been talking for a long, long time about starting a blog about how we can use insects to inspire new technologies. One of these friends who had to humor me for so long is Nils Cordes. I met Nils when he was a student at Illinois, but he is currently finishing up his PhD at the University of Bielefeld in Germany. Nils is a great scientist, and a great communicator. He is also a wonderful artist. He offered, those many years ago, to create some art work for this (then still imaginary) blog that I was going to use to communicate my love of insects. And he did…behold the best blog banner EVAH!

 

 

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Introducing Engineering Students to BioInspiration

Creativity, Innovation and Vision Courses

At this point in the semester I introduce myself to the students in the Engineering courses with the title Creativity, Innovation and Vision.  There is both an undergraduate (ENG333) and a graduate version of this course (ENG598).

The originator of the course is Dr. Bruce Litchfield. Students in these courses learn that their own state of creativity is not as static as they might expect. Bruce and his collaborators also do research on creativity enhancement; paying special attention to the ways in which engineering students currently incorporate creativity, since it has been shown that for engineering students creativity does not increase as they move through their college courses (the same is likely to be true for students in other disciplines).(1)

The descriptions for the CIV courses are:

“Personal creativity enhancement via exploration of the nature of creativity, how creativity works, and how to envision what others may not. Practice of techniques and processes to enhance personal and group creativity and to nurture a creative lifestyle. Application to a major term project providing the opportunity to move an idea, product, process or service from vision to reality.” (2)

The courses are quite popular with students from all over campus, not just Engineering.  Many of the students who take the graduate level course become teaching assistants for the undergraduate course in subsequent semesters. (I think in this case the term ‘facilitators’ instead of TA is more applicable)

BioInspiration (formerly BioCreativity)

Over the last ~3 years I have worked with Bruce and the TAs on a module we call BioCreativity BioI.  It is basically a module on BioInspiration or Biomimicry. I now kind of regret coming up with yet another term for a field of study that suffers from much confusion due to terminology already, but students seem to like the title because it fits into the focus of the course so perfectly. However, if we adhered to proper terminology more rigorously it should be acknowledged that BioCreativity is actually the combination of biology and art, not biology and technology, as we use it here. [Note: in 2014 we realized that the term Biocreativity created too much confusion and we decided to name this module BioI or BioInspiration].

The BioInspiration module is divided into four class meetings and each meeting is separated by 2 or 3 weeks [Note: in 2014 we also decide to condense the module since students felt they were not able to focus on this one task if they had all these other topics being thrown at them too.]  This week I met the students of two ENG333 sections. This semester a large majority of students are engineers (mechanical, chemical, civil, electrical, bioengineering). A number of students are computer science majors, and advertising majors. A couple of students are majoring in the arts, such as creative writing and graphic design. Students from the humanities are also represented, by majors in philosophy and anthropology. In other words, it is quite a diverse group of students eager to learn how to enhance their creativity.

During our first meeting this past week I introduced the students to the topic of Biocreativity.  I mostly talked unscripted, but I also had a pretty PowerPoint behind me with amazing pictures by Alex Wild (http://www.alexanderwild.com/). [Note: in 2014 the course will have 7 or more sections. Too many for me to visit. We have decided to therefore put this first lecture on video which will be presented to the students during the class.]

  • I continued the introduction by explaining how I became interested in Bioinspiration. I like to tell the students that it is all my husband’s fault. I am married to a mechanical engineer and over the 25 years that we have known each other, we have taken many a road trip. Usually during these trips we end up “discussing” why insects are better/worse at “doing stuff” than human engineers. In the beginning (the first 24 years) he always ended the argument by saying something like: “Well, sure that might be a cool thing that insects can do, but can they fly 500 people across an ocean? No? Well, there then!” My interest in teaching modules, courses, and now this blog on Bioinspiration is all because I really want to learn how to win this argument.
  • "Biomimicry Shoe" by Marieka Ratsma and Kostika Spaho. Interesting, definitely. Pretty, maybe.Biomimicry, definitely not.Photograph by Thomas van Schaik.

    Biomimicry Shoe” by Marieka Ratsma and Kostika Spaho. Interesting, yes. Pretty, maybe. Biomimicry, definitely not.
    Photograph by Thomas van Schaik.

    I then very briefly explained what I mean by Biomimicry and Bioinspiration. I do this quickly because the topic of definitions might evaporate all creativity out of these students. I put up Janine Benyus’ (Biomimicry3.8) Life’s principles, and also Robert J. Full’s quote about evolution working on the just good enough principle.  I actually spend more time on what I think biomimicry and bioinspiration is not. Students see these types of examples often in popular media because the terms have become buzzwords.

  • Why have biomimicry and bioinspiration become buzzwords? In my opinion it is probably because people like to think that if we copy/mimic/emulate nature, or at least base some or our new engineering designs on nature, then it is probably also more sustainable. And sustainability is itself a buzzword. I stressed in my presentation that that is not necessarily the case. The most famous example of bioinspiration is probably Velcro, which is made from synthetic materials that are not biodegradable and cost a lot of energy to produce.  For many scientists who are inspired by nature and use biomimicry or bioinspiration as a guide it is not sustainability per se that drives them. It is a guide to making new basic biological discoveries, or to innovate and solve a technological problem. “Why does an animal or a plant do that? And how can we use that what I have learned in a new technology?”
  • Next I make a very controversial statement: “I think my husband is basically correct.”  Of course, nature has not been able to carry 500 people across an ocean. Primarily because of the issue of scale. Nature works at a much smaller scale than we humans usually do. However, we currently live during very exciting times, where we can find inspiration for innovation at a smaller scale. We can now image at the nano-scale. That means that we can see structures and processes at a scale where very important things in nature happen. At the same time we are starting to be able to manufacture at that size scale too. We can start to build structures the way that nature builds materials and structures; hierarchical and from the bottom up.
RulerAnt

Dinoponera australis. Photograph by Alex Wild. http://www.alexanderwild.com.

  • Just consider an ant. Think of the interesting aspects of an ant’s body and life history. All these apsects have the potential to inspire us. (These are subjects I will blog about in greater detail at a later point).
  1. Exoskeleton (cuticle). Multifunctional. Made from relatively few elements (compared to all the elements from the periodic table we use to manufacture our multifunctional materials). One individual often has cuticle that has different characteristics – soft (larva, abdomen) or hard (adult, head), for instance. And on top of that, when molting occurs in the larval stages most of this cuticle is recycled and used in the new cuticle. No toxic substances required. All of life’s principles satisfied.
  2. Located on the surface of the cuticle are nanostructures that can help capture moisture, or give an insect color (as is the case in the Morpho butterfly).
  3. The locomotory mechanisms of insects, including ants, has inspired many bioinspired robots. I have tried to keep up with all the different bioinspired robots on this Pinterest Board.
  4. Insects, even tiny ones like this ant, have many interesting sensors on their bodies: compound eyes, simple eyes, antennae, mechanoreceptors, etc.
  5. Ant and termite nests have also been of interest for bioinspired architecture since through cooperative behavior they can build structures that are relatively stable and require few inputs (Again, unlike our own structures).
  6. And sociality in ants, the cohesion that exists between these “small brained” insects, has inspired electrical and computer engineers.
  7. And so on.
  • These are all examples of inspiration points from just an ant.
  • By this point it was my hope that students understand the possibilities that exist. I gave them some tips on how they can become “bioinspired”.

Avenues to becoming BioInspired (as a student in CIV)

1. Delve into biomimicry and bioinspiration basics

Students were asked watch two videos before the next BioCreativity meeting.

  1. Dayna Baumeister from Biomimicry3.8 at 2011 Bioneers conference  (her talk starts at 4:50min)
  2. Robert J. Full from UC Berkeley – TED talk entitled Engineering and Evolution

2. Delve into biomimicry and bioinspiration history

Students are encouraged to review some “famous” examples of bioinspired design.

Some general articles that introduce the topic:

The incredible science behind how nature solves every engineering problem. Business Insider. Jennifer Welsh. March 14, 2013.

Non-insect Top 10 (These are the most famous examples, I do not agree that all of these are in fact bioinspired or have been successful*):

  1. Cockleburs -> Velcro
  2. Lotus leaf -> Self-cleaning materials
  3. Gecko -> Gecko tape
  4. Whale fins -> Turbine blades
  5. Box Fish / Bone -> Bionic car
  6. Shark skin -> Friction reducing swim suits*
  7. Kingfisher beak -> Bullet train
  8. Ecosystems -> Industrial symbiosis
  9. Coral -> Calera cement*
  10. Forest floor / Ecosystem functioning -> Flooring tiles

Insect Top 10: I will cover all of these examples in detail in this blog.

  1. Morpho butterfly structural color
  2. Namib beetle water collecting
  3. Cockroach walking/running
  4. Insect flight
  5. Termite mound passive cooling
  6. Bee swarming
  7. Collembola skin
  8. Mosquito inspired microneedle
  9. Insect foot adaptations for adhesion
  10. Cockroach campaniform sensilla for sensing

Change your surroundings and go outside into nature

Here are some resources for when you go out into nature:

  1. Secrets of Watching Wildlife
  2. Get to know nature by keeping a journal

Go inside to view nature

Change your perspective

  • Look at things from different, less familiar angles. Look at a whole tree (Why is a tree that shape?), go closer (Why is the bark textured like that?), go even closer (Why does moss grow in those crevices).
  • Sketch or take pictures
  • Bring your friends – talk about what you are seeing.
Leonardo Da Vinci's sketch of a bird in flight. http://commons.wikimedia.org/wiki/Leonardo_da_Vinci

Leonardo Da Vinci’s sketch of a bird in flight.
http://commons.wikimedia.org/wiki/Leonardo_da_Vinci

See what others are doing

  1. http://zqjournal.org/
  2. http://bouncingideas.wordpress.com/
  3. http://bioinspiredink.blogspot.com/
  4. http://ciber.berkeley.edu/
  5. http://wyss.harvard.edu/
  6. http://templebiomimetics.wordpress.com/category/bioinspiration/
  7. http://ase.tufts.edu/biology/labs/trimmer/
  8. http://www.biokon.net/index.shtml.de
  9. http://swedishbiomimetics.com/
  10. http://www.fastcompany.com/biomimicry
  11. http://inhabitat.com/index.php?s=biomimicry

Find inspiration on the web (look at great pictures of nature, read great stories about biology).

Go to the bookstore or library

BookCovers

Bioinspiraton and Biomimicry book covers from my eReader and at my lab.

  • Cats’ paws and catapults: mechanical worlds of nature and people. Steven Vogel. 2000
  • Biomimicry: Innovation inspired by nature. Janine M. Benyus. 2002
  • The gecko’s foot: bio-inspiration: engineering new materials from nature. Peter Forbes. 2006
  • Bulletproof feathers: How science uses nature’s secrets to design cutting-edge technology. Robert Allen. 2010
  • Biomimetics: Biologically inspired technologies. Yoseph Bar-Cohen. 2005
  • Biomimicry in architecture. Michael Pawlyn. 2011
  • Biomimetics in Architecture: Architecture of Life and Buildings. Petra Gruber. 2010
  • Biomimicry: Innovation inspired by nature. Janine M. Benyus. 2002
  • The smart swarm: How to work efficiently, communicate effectively, and make better decisions using the secrets of flocks, schools, and colonies. Peter Miller. 2010
  • Learning from the octopus: How secrets from nature can help us fight terrorist attacks, natural disasters and disease. Rafe Sagarin. 2012
  • Darwin’s devices: What evolving robots can teach us about the history of life and the future of technology. John Long. 2012.
  • How to catch a robot rat: When biology inspires innovation. Agnes Guillot and Jean-Arcady Meyer. 2010.
  • Etc.

Use Social media

For example Twitter. I suggest you follow these folks because they often tweet links to interesting bioinspiration or biomimicry (and thus biocreativity) topics.

And then I sent the students off into the world, to get inspired. Actually, I explained a little bit more about the project we want them to do, but I will leave those details until the next blog post about BioCreativity.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

(1)  This research by Burgon, et al. (under review) measured the creativity of first- and fourth-year engineering students using two nationally-normed creativity assessment instruments. I will blog more about this work when it has been published.

(2) More information about the Creativity, Innovation and Vision courses:

Two videos that introduce the topics discussed in the courses can be seen here:

  1. Part 1: http://youtu.be/6Csl7VPaG1k
  2. Part 2: http://youtu.be/c4BIa1RtpnI

And here is a pdf of  the First Day Course Pack.