Ultra light/thin yet stiff material 5

[vidiii]

Hi,

Does anybody know thin and light but stiff materials that could be used for wing material for the development of insect-like micro aerial vehihicles.

The price is not very important, however it is prefered that international suppliers can ship it (to Europe).

Any suggestions are very welcome. I hope to hear from you soon.

Thank you

 

[CoryPad]

carbon fiber-reinforced composites

 

[RPstress]

Diamond. Specific E = 30 million meters (roughly isotropic).
Cytec K-1100 pitch-based carbon fiber. Specific E along fiber = 45 million meters.
Toray M70J PAN-based carbon fiber. Specific E along fiber = 36 million meters.

 

[RPstress]

Oh, and beryllium, specific E = 16 million meters (isotropic). A not-very-tough metal, but eminently workable (though toxic).

If you managed a 70% fiber volume fraction polymer composite with M70J for an isotropic laminate you'd have roughly specific E = 8 million meters.

For a non-quasi-isotropic layup which might be reasonable for a wing (say 60/30/10 percentages in 0, 45 and 90 degree directions) you might manage about 15 million meters along the 0 degree axis.

I guess you can also have sapphire (AL2O3) specific E = 11 million meters (roughly isotropic).

 

[vidiii]

Thank you very much for your replies.

Do you know or have experience with international suppliers with quick shipment of thin sheets of carbon fiber-reinforced composites (CFRP of 0.5 to 0.1 milimeter sheets in very small quantities, because its for making a small prototype).

 

[unclesyd]

I worked on a project where we were adding reinforcement to to thin films (4" x 4") of various plastics, Kapton, Mylar, Nylon, and several others. Most of the work was orientated toward using CF to reinforce the films. As I recall one method was to attach the CF to the film and then metallized. The fiber was prepegged and then applied to the film with heat and pressure.
Again recalling it was this approach that gave the highest stiffness product in the thinnest sheets.
Still recalling I believe that Kapton had the highest stiffness of any of the thin film materials as received.

I would look at NASA as they have done a lot of work in the area of rigidizing thin films for space use.

 

[RPstress]

For carbon fibers you could try epo in Germany (

http://www.epo-gmbh.de/

) or Hexcel or Toray (

http://www.soficar-carbon.com/

) in France. Getting extreme raw materials shipped from the States can be a problem because of export controls. Small quantities will of course always be a problem.

I think unclesyd's more non-conventional suggestions have merit.

 

[Compositepro]

When you consider the loads involved in insects and micro vehicles (i.e., very low) these exotic materials usually don't work. Low density is often more useful than high strength. High Youngs modulus will not compensate for low section modulus and once you have adequate section modulus you don't need high youngs modulus. An analogy is that a wood 2x4 can be stiffer than the same weight of steel bar.

 

[Neubaten]

Al-Li?