iMechanica - iMechTube - Comments

Embedded YouTube movie can not be shown

Kejie Zhao — Sat, 13 Oct 2007 22:07:19 -0400

Hi Prof. Li,

Many thanks for the clear steps of posting a vedio. But now I find the embedded YouTube movies can not be shown, only left a yellow block area, in my blog. I also find this problem is encountered in other recent posts of Channel vedio. I hope this is my Internet Explore problem, but not a general one. Thank you

Kejie Zhao

Gecko and fluids

Aaron Goh — Sun, 30 Sep 2007 10:51:07 -0400

Can a gecko climb a wet wall, e.g. after the wall is exposed to rain? What about a wall which is freshly painted and the paint is not dry yet?

Video posting in iMechanica becomes much easier

Teng Li — Thu, 10 May 2007 13:06:39 -0400

iMechanica has upgraded to Drupal 5.0 . The function of the text editor, TinyMCE, is also enhanced. Now posting a video become much easier.

In the orginal post above, the 5-step instruction involves turning on/off TinyMCE to post a video in iMechanica, which turns out to be tricky to many iMechanicians. Now you can post a video without changing your texteditor setting. A simplified 4-step instruction is given below:

Step 1: Sign up a free account at YouTube.com, a website you can share videos online. Upon sign up, you can upload videos to YouTube. Follow the easy directions there. Of course you may want to read copyright tips of YouTube before uploading.
Step 2: Once uploaded, your video will have a Unique URL. You can always
provide a hyperlink of the video in your post. To directly embed the video into a post, you need to use the html code automatically generated by YouTube, which you can easily find below the unique URL in the video information. Copy the entire html code.
Step 3: Start to post a new entry. First, type in all the text part of post, and leave a blank line for the video to be embedded. Then click the "HTML" button in the TinyMCE toobar. A HTML Source Editor window will pop up, in which are the text you just typed in and some html tags. Locate the blank line and paste the html code from Youtube there. Click the "Update" button in the pop-up window.
Step 5: A yellow block in the main text editing box indicates the video has been embedded. Preview then submit. Now all iMech users can view your video without leaving your post!

Enjoy vlogging in iMechanica!

Many thanks

Tienchong Chang — Mon, 08 Jan 2007 20:47:48 -0500

Hi, Haimin,

Thank you so much for your useful information.

It has been reported that

Haimin Yao — Fri, 29 Dec 2006 05:05:14 -0500

It has been reported that the fibrillar structure of gecko has a self-clearning mechanism. Please see the following paper:

W. R. Hansen, and K. Autumn, Evidence for self-cleaning in gecko setae, PNAS, 102 385-389.

I have a question about gecko

Tienchong Chang — Wed, 27 Dec 2006 00:14:31 -0500

How does a gecko get its foot clean if where some minor dusts (with diameters in several nanometers) were attached?

How to climb a wall

Jose Berengueres — Tue, 26 Dec 2006 15:48:26 -0500

http://www.youtube.com/watch?v=5_yFpOh7-Hg

http://www.youtube.com/watch?v=Yw1k_u7MjMs

TOUGH QUESTION

Jose Berengueres — Fri, 08 Dec 2006 14:07:24 -0500

by the way ,

Does anybody Know how to make a 30 micrometer fiber

with a conducting core of dimater 20 um covered by an 5 um insulating skin?

I am using carbon nanotube mixed with polymer and extrusion process

but my 30um fibers are not conducting ><

spiderman

Wall Climbing

Jose Berengueres — Fri, 08 Dec 2006 14:02:37 -0500

That s the million RMB question...

I will explain

how to climb a

normal wall

IEEE ROBIO

during the presentation tittled...

Gecko inspired Electrostatic Chuck

(in 2006.12.17 Kunming)

spiderman

Interesting

Haimin Yao — Fri, 08 Dec 2006 11:54:26 -0500

Unfortunately, I have not seen this spiderman in this MRS meeting.

I am just wondering if this spiderman can climb on the normal wall instead of the "iron" wall as shown in the movie.

Haimin Yao

More Literature

Jose Berengueres — Tue, 05 Dec 2006 12:59:22 -0500

Six mechanichal properties of living gekco foot hair can be founf at:

Shape of spatular pads
Spolenak, R., Gorb, S., Gao, H. J. and Arzt, E. (2004). Effects of contact shape on the scaling of biological attachments. Proceedings Of The Royal Society Of London Series A-Mathematical Physical And Engineering Sciences 461, 305-319.

Lever effect
Autumn, K., Liang, Y. A., Hsieh, S. T., Zesch, W., Chan, W.-P., Kenny, W. T., Fearing, R. and Full, R. J. (2000). Adhesive force of a single gecko foot-hair. Nature 405, 681-685.
Autumn, K., Dittmore, A., Santos, D., Spenko, M. and Cutkosky, M. (2006). Frictional adhesion: a new angle on gecko attachment. Journal of Experimental Biology 209, 3569-3579.

Cantilever Effect / Roughness
Campolo, D., Jones, S. D. and Fearing, R. S. (2003). Fabrication of gecko foot-hair like nano structures and adhesion to random rough surfaces. In IEEE Nano 2003 Aug 12-14, vol. 2, pp. 856- 859. San Francisco: IEEE.
Majidi, C., Groff, R. and Fearing, R. (1995). Attachment of fiber array adhesive through side contact. Journal of Applied Physics 98, 103521.
Persson, B. N. J. and Gorb, S. (2003). The effect of surface roughness on the adhesion of elastic plates with application to biological systems. Journal of Chemical Physics 119, 11437.

Peeling Effect
Gao, H. J., Wang, X., Yao, H. M., Gorb, S. and Arzt, E. (2005). Mechanics of hierarchical adhesion structures of geckos. Mechanics of Materials 37, 275-285.

Stiffness Asymmetry
Yao, H. and Gao, H. (2006). Mechanics of robust and releasable adhesion in biology: Bottom-up designed hierarchical structures of gecko. Journal of the Mechanics and Physics of Solids 54, 1120-1146.
Autumn, K., Majidi, C., Groff, R., Dittmore, A. and Fearing, R. (2006). Effective elastic modulus of isolated gecko setal arrays. Journal of Experimental Biology 209, 3558-3568.

Moment distribution
Glassmaker, N. J., Jagota, A., Hui, C. Y. and Kim, J. (2004). Design of biomimetic fibrillar interfaces: 1. Making contact. J. R. Soc. Lond. Interface 1, 1-11.
Hui, C. Y., Glassmaker, N. J., Tang, T. and Jagota, A. (2004). Design of biomimetic fibrillar interfaces: 2. Mechanics of enhanced adhesion. J. R. Soc. Lond. Interface 1, 12-26.

And they correlate with those properties found in the magnetic hair. (Courtesy of a referee of bioinspiration & biomimetics). By the way, Boston: a really neat city.

Spiderman ;)

Attractive and insightful research

Cai Shengqiang — Tue, 28 Nov 2006 03:05:04 -0500

The research about the mechanics of gecko foot-hair is one of my most interested works. The nano size, hierarchical structures of the gecko foot-hair could be clearly explained by some basic theories of fracture mechanics. The explantions about the switch between adhesion and deadhesion is also convinced.

The research by the group of Prof. Gao and most of other researchers assumed that the adhesion between gecko foot-hair and substrates only comes from van der waals force. But, some recent experimental researches showed that the capillary force maybe give some contributions to this adhesion. I think the experimental results may be helpful for us to understand the interesting mechanic problems more comprehensively, so I attach the link of this paper here:

http://www.pnas.org/cgi/content/full/102/45/16293

Mechanics is part of science and technology.

Recent studies on the mechanics of gecko foot-hair

Teng Li — Tue, 28 Nov 2006 00:21:36 -0500

There have been some substantial progresses in understanding the mechanics of gecko foot-hair in the past several years. Here are some representative papers:

Arzt et al PNAS 2003

Gao and Yao, PNAS 2004

Gao et al Mech. Mater. 2005

If you're aware of more in literature, welcome to add to this list. Thanks.

-Teng

Tube of science & technology

Teng Li — Sun, 26 Nov 2006 22:55:48 -0500

Zhigang, Thanks for the heads-up. The idea of Journal of Visualized Experiments is interesting. It provides a more academic channel to broadcast videos on science & technology. It's a decent place to publish videos, but has much less audience than YouTube (at least for now). I'll be interested in how it will progress, since I'm not quite sure if it is really a good idea to increase the entry barrier for researchers who want to share their videos online.

-Teng

YouTube for test tubes: a report in Nature

Zhigang Suo — Sun, 26 Nov 2006 11:18:01 -0500

Here is a report in Nature on how scientists are using YouTube, or reinventing it. Teng and Ravi: You guys were ahead of the game.