Author Topic: Directional Friction material. (Read 13558 times)

bukowski · « **on:** January 25, 2008, 01:38:26 PM »

I was wondering if anyone had seen some kind of material that has high friction while sliding on a surface one way, but very low friction while sliding the other way. I had an idea for a simple mini bot...

SmAsH · « **Reply #1 on:** January 25, 2008, 02:03:13 PM »

i dont think there is anything like that...but you could use a trail of something going one way...

~smash

airman00 · « **Reply #2 on:** January 25, 2008, 02:08:14 PM »

what about something like this

its looks like a triangle

you can push up side C but once you get over side C , side B blocks you from going backwards. If you have a lot of these triangles you could create a one way only drive system ( sumo robot anyone )

ed1380 · « **Reply #3 on:** January 25, 2008, 04:36:39 PM »

how big?

you could use one of those zip ties. cut the clicking part off and mount it to whatever and have the actual zip tie as a track for it to ride one

and maybe the barbed part from velcro

hazzer123 · « **Reply #4 on:** January 25, 2008, 04:47:16 PM »

Look to nature for this type of material. Shark and snake skin has this property.

http://www.enchantedlearning.com/subjects/sharks/anatomy/Skin.shtml

bukowski · « **Reply #5 on:** January 25, 2008, 06:43:39 PM »

Yeah, something like that.
I had in mind a really simple idea of having two blocks, with an inductor/electro magnet on each and circuitry to switch the polarity. The object is to have kind of an inchworm. Not very practical, it would be omnidirectional, but it would be a fun experiment. The problem is getting it to move forward, not just stay in place.

Admin · « **Reply #6 on:** January 31, 2008, 02:19:32 PM »

Let me know if you find a material, I could use it for my micro-robotics projects.

This material you are asking for is one of the holy grails of micro/nano robotics yet to be solved, but I'm sure something exists already not yet 'discovered'.

krich · « **Reply #7 on:** February 01, 2008, 02:20:41 PM »

How about this.

[youtube]http://www.youtube.com/watch?v=NSb0IAU9sWw[/youtube]

cooldog · « **Reply #8 on:** February 01, 2008, 02:43:57 PM »

Quote from: krich on February 01, 2008, 02:20:41 PM

How about this.

[youtube]http://www.youtube.com/watch?v=NSb0IAU9sWw[/youtube]

i'm accually gathering materials to use those as floor scrubers

ed1380 · « **Reply #9 on:** February 01, 2008, 04:49:27 PM »

HOLY SH*T that bristle bot thing is sweet

BANE · « **Reply #10 on:** February 01, 2008, 05:24:58 PM »

What if you were to get four of them and attach them and some wire (like a quad brush

). Then make a very light controller that can control each side of the bot with on/off for steering. (gotta try that one

)

bane

Admin · « **Reply #11 on:** February 03, 2008, 05:25:39 PM »

nice find krich!

. . . use two toothbrushes, hook it up to RC, and get differential drive control

they also had another there:
[youtube]KpHGE4wAfKQ[/youtube]

gamefreak · « **Reply #12 on:** February 03, 2008, 05:31:05 PM »

lol, make an SOR fundraiser and sell these toys

airman00 · « **Reply #13 on:** February 03, 2008, 05:41:55 PM »

very interesting idea with the brushes!!!!

I'll put this into my notebook of robotics projects!!!

One question , this works with tooth brushes only , right?

where can I find a big brush which demonstrates the same properties?

Admin · « **Reply #14 on:** February 03, 2008, 05:53:11 PM »

Quote

One question , this works with tooth brushes only , right?

where can I find a big brush which demonstrates the same properties?

It's not the tooth brush but actually the directional friction. The brushes are angled, so one way is pointy, the other way is smooth.

When the brush vibrates, the brush will move in the direction of least resistance - away from the high friction direction.

People have suggested that you can build a nano-robot by putting a brush of angled carbon nano-tubes on it and then vibrating it to move.

airman00 · « **Reply #15 on:** February 03, 2008, 05:57:38 PM »

Quote from: Admin on February 03, 2008, 05:53:11 PM

Quote
One question , this works with tooth brushes only , right?

where can I find a big brush which demonstrates the same properties?
It's not the tooth brush but actually the directional friction. The brushes are angled, so one way is pointy, the other way is smooth.

When the brush vibrates, the brush will move in the direction of least resistance - away from the high friction direction.

People have suggested that you can build a nano-robot by putting a brush of angled carbon nano-tubes on it and then vibrating it to move.

Oh ok, thanks for explaining .

Now can I buy a larger sized brush , that has these angles? Link to seller please

(p.s. im searching myself now also)

Trumpkin · « **Reply #16 on:** February 04, 2008, 10:21:50 AM »

you asked for a big toothbrush, here is a big toothbrush! LOL

http://www.greatbigstuff.com/toothbrush.html
something a little more practical http://www.thatrestlessmouse.com/product/PR7202/GIANT_super_toothbrush.html

cooldog · « **Reply #17 on:** February 04, 2008, 05:20:49 PM »

on instructables they say you can use a vibrator from a old games system controler

bukowski · « **Reply #18 on:** February 04, 2008, 07:04:15 PM »

OK, after a bit of legwork, I think the technical term for what I was looking for is Friction Anisotropy, or in nature, dentricals. There is some material that US olympic swim teams use on their swimsuits that is supposed to have this property, and there are a bunch of people doing experiments with nanotubes to get these results, but for now, the brush idea looks great. Going to give it a shot.

gamefreak · « **Reply #19 on:** February 05, 2008, 10:52:09 AM »

isnt true nanorobotics basically building a life form? In what way is a robot that reacts when it hits something or gets poked not like a single celled organism? What defines that a robot is not alive? They can communicate, they can react. When the human mind is finally cracked, what limits that from being reprogrammed like a robot?

One of these days I will have an army made of thousands of toothbrush robots. My enemies shall quiver at the site of..... THE HYGEINE PATROL!!!!

Steve Joblin · « **Reply #20 on:** February 05, 2008, 11:00:41 AM »

Quote from: gamefreak on February 05, 2008, 10:52:09 AM

In what way is a robot that reacts when it hits something or gets poked not like a single celled organism? What defines that a robot is not alive? They can communicate, they can react. When the human mind is finally cracked, what limits that from being reprogrammed like a robot?

That is part of it... reproduction is the other... a cell can devide and make copies of itself... a robot can't (well, at least not yet!)

gamefreak · « **Reply #21 on:** February 05, 2008, 04:02:48 PM »

A robot arm could tottaly be designed to make copies of itself, it couldnt even be programmed to order the parts to remake it self

noone has done it since there is no reason too, but it could happen

krich · « **Reply #22 on:** February 05, 2008, 06:23:04 PM »

Okay, fess up gamefreak. You had to look up how to spell hygeine. :-p

My daughters and I made a bristlebot this weekend. We used a vibrating motor off a bad Xbox controller, a 9v battery, three toothbrush heads, and a piece of cardboard for the platform. She also decided to add LEDs for eyes.

She wanted to take it to school for show and tell, so she made a UTube video of it to send her request to her teacher. Do a search on "RoachMobile" and you'll find it. I'll post a link once I get off work.
It was a hit with the 10-11 year old crowd. About 15 minutes of work. Awesome! Excellent bang for the (buck + effort).

Ken

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Author Topic: Directional Friction material. (Read 13558 times)