iMechanica - adhesion - Comments

Biomimetics story in National Geographic

MichelleLOyen — Fri, 11 Apr 2008 08:47:58 -0400

There is an article on biomimetics in National Geographic , highlighting yet again that this is one of the future directions for engineering.

(How was it that biomimetics was missed in the NAE list of Grand Challenges in Engineering ? I'm still convinced that they missed the boat with the medically-related topics they included, but even if you ignore direct medical applications, the idea of "learning from nature" to engineer new products and ideas has been quite prevalent in the last few years. )

Mechanics in Bone Biomimetics

MichelleLOyen — Sun, 10 Feb 2008 17:07:50 -0500

My summary of bone mechanics, materials science, and biomimetics is in the MRS Bulletin this past issue (January) which was where I derived the idea for this broader J-club topic on mechanics in biomimetics in other systems. We are very excited to be preparing a potential new course on this subject for 2008-9 at Cambridge.

Rohit, Zhigang summarized

Pradeep Sharma — Wed, 09 Jan 2008 21:12:12 -0500

Rohit,

Zhigang summarized very well the rationale for going to a two-week format for the j-club. His last point is particularly important, the frequency of the j-club, like so many other aspects of iMechanica are an experiment (inexpensive to conduct, I might add). We expect to re-evaluate the bi-weekly format at the end of this year.

Regarding discussion, different topics will generate different amounts of discussion. In my personal opinion, it is not the j-club mission to necessarily promote topics that will generate a "large" number of comments. As long as the topic remains of interest to cross-sections of the community, it is good. Often, and I know this from personal experience, many mechanicians are content to simply read the j-club (or for that matter other posts) but do not post comments. These mechanicians are, still, very much interested and appreciative of the actual posts. As example, the present issue on Biomimetics was very useful to me since I learned a lot about this subject (which happens to be outside my area). I posted no comments however, but followed the discussion carefully and read through some of the papers recommended by Michelle.

Why do we have a new Theme of jClub every two weeks?

Zhigang Suo — Wed, 09 Jan 2008 17:56:10 -0500

Here is a thread of discussion on running a new Theme every two weeks. The main points are

Mechanics is a diverse field. Few Themes will interest everyone. There is no reason to select a Theme to interest everyone. (We can only have one President, but we can have many Themes.) However, if a particular Theme does not resonate with a person, she would have to wait for a month for another new Theme.
By removing the need to be popular, a Discussion Leader may better focus on the mission of the jClub: to foster discussion at the frontier of mechanics and its applications.
Much of discussion for the past Themes seemed to occur in the first 2 weeks following the initial posting.
Even after a Theme has become an old one, you can always access it by clicking the tab Journal Club on the right side of iMechanica. You can always discuss any old Theme further.

Of course, every change on iMechanica is just an experiment. It would be interesting to hear from people on pros and cons of any change.

Role of mechanics in biomimetics--inactivity

Rohit Khanna — Wed, 09 Jan 2008 16:47:36 -0500

hi All,

I want to know about the inactivity of this discussion topic. Isn't it important to have a discussion on role of mechanics in biomimetics...or we don't have experts in this field in the current list of users.

I also have a question about why it was decided to have only 2 weeks . I hope some responsible member of the forum should be able to answer these.

I am just curious to know about this.

Rohit

Re:Macro-biomimetics

Ying Li — Mon, 07 Jan 2008 03:26:39 -0500

Interesting topic! Actually，in our previous work, the sandwich structure of the dragonfly wing vein was supposed and its exceptional mechanical properties were also explored. Recently, the direct experimental results on this sandwich structure were also found . We are trying to utilize this unique microstructure to design the the new micro air vehicle (MAV), especially ornithopter.

Biomimetics-An inspiration from nature

Rohit Khanna — Fri, 04 Jan 2008 13:32:11 -0500

Hi All,

Well, one of the most awaited topic for me at least. Thanks to Prof. Michelle.

Discoveries from the past elucidate that people have been inspired by nature. Joseph Paxton used the design of a lilypad to structure the Crystal palace, Wright bothers used the idea of bird wings to structure planes, material scientists used many naturally made structures like snow-flakes, honeycoumb structure to build a strong aircraft design. Being from materials background, i can recapitulate that the research in the field of material science has been evolved through many stages, metallurgist employed metal's ductility to improve brittleness, where ceramists are always interested in improving brittleness....and then comes composites which is a compromise between metal and ceramics, it has been fascinating that engineers have been successful in taking these materials to application stage. But question is: did they ever heard of biomimetics? I think it is the impulse which drives the science and technology. It is true that man made components are not as perfect as nature's.

We have to learn a lot from nature.

As far as research in field of bone tissue engg is concerned, nowadays the urge is to build three-dimensional porous scaffolds to be used as implants inside the body. It has still not reached to clinical practices. It is a new emerging area which needs contribution from mechanicians, material scientists as well as biologists. Mechanicians can help us to understand the invivo stresses generated on implant and to surrounding tissues which are again time-dependent strains...so there is a need to understand viscoelasticity under such a situation..... material scientists need to design a strong and biocompatible and biodegradable material ....and of course the knowledge of cell biology is paramount.....you can now realize the Potential of the biomimetics field.which opens up demand and pathways for interdisciplinary commitments..it is definitely a promising field which is still untouched by many, and this is going to last forever. It needs a great contribution from great researchers like you.

Rohit

Re:

Rohit Khanna — Fri, 04 Jan 2008 11:47:09 -0500

Thanx Henry for the response. There are already materials and engineering structures which are in use and are adopted from nature.

Nowadays the focus of biomimetics is shifting towards synthesizing and designing the materials which can be used an implants inside the human body(for e.g for bone tissue engineering applications). Existing knowledge is limited to understanding of materials and partially to design of such kind of materials. The missing component is the Functionality... how does cells responds to the surface of the material, do materials offer toxic response or leave products which are not biodegradable? Knowledge of the structure and design is just not sufficient, functionality invivo is the major consideration. That's where the role of mechanics is very important.

Rohit

learn or use?

Henry Tan — Fri, 04 Jan 2008 10:04:24 -0500

Learn from nature and develop mechanics is good, but it is better to use nature directly and grow materials and structures.

Links

Mats Brodén — Thu, 03 Jan 2008 05:21:13 -0500

http://academic.brooklyn.cuny.edu/userhome/psych/fgrasso/people.html

Frank Grasso

http://ciber.berkeley.edu/twiki/bin/view/CIBER/CenterRecruitment

Robert Full

http://www.ted.com/talks/view/id/195

I find these two guys very interesting.

I will most likely be working with Encyclopedia of Life in Sweden. I would like to set up a seminar about how we represent animals and plants movements in Stockholm. I'm looking for projects that deals with this. I don't really know how iMechanica works.

Mats

macro-biomimetics and movement

MichelleLOyen — Wed, 02 Jan 2008 17:08:33 -0500

You are absolutely right, there is an entire additional category of biomimetics research concerned with animal dynamics and movement. Particular areas of interest are walking, flight and swimming for making robots that move more naturally and easily than typical man-made robots. I thought that the topic was too far from my own expertise to do justice with paper selection, but perhaps I can track down a volunteer to highlight this topic for a later issue of the j-Club this year. Thanks much for bringing this up.

Perhaps not all individual hair filaments are engaged?

Nachiket Gokhale — Wed, 02 Jan 2008 13:33:24 -0500

Perhaps the reason could be that not all hair filaments are engaged in the act of adhesion. It could be that the probabilities work out in such a way that for each step the Gecko takes, only a few hundred individual hair filaments get entanged with the underlying surface.

-Nachiket

Biomimetics at macroscale?

Teng Li — Wed, 02 Jan 2008 11:27:43 -0500

First all, congrats to Pradeep and Michelle for a fruitful year of iMech jClub in 2007! It has been a vital part of iMech at its early begnining, and I'm sure it will still be in the future growth of iMech. Look forward to another successful year of iMech jClub!

This very first theme in 2008 is quite interesting. Biomimetics at micro-/nanoscale has been a surge of interest in the past several years. I'm also curious about any progress in the biomimetics field at macroscale. For example, the vehicles (in air, or under water) that can morph their structures during service to mimic birds or fishes. Definitely mechanics plays an important role in enabling such morphing vehicles. I'm wondering if anyone can point out the state of the art in this emerging field.

The topic is really nice and

Yujie Wei — Wed, 02 Jan 2008 09:43:50 -0500

The topic is really nice and timely. I am sure that most members will learn something from the discussion and appreciate your work.

I attended a seminar on mimicking biology several weeks ago. The speaker, Prof. Roger Hanlon from Woods Hole, showed a camouflage octopus vedio, which may be of the interest of our members.

http://video.google.com/videoplay?docid=-4139449748454943279

millions of hairs, why only hundreds of times hanging force?

Henry Tan — Wed, 02 Jan 2008 09:12:36 -0500

A question to ask:

A gecko has millions of hairs on each foot. Why their combined adhesive force is only hundreds of times greater than what is required for the gecko to hang from a ceiling by one foot?

There must exist a unique adhesion mechanism that I do not know.