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Let's say you are cleaning some USB ports/plugs with chenille pipe cleaners moistened with alcohol. As you can see from the image of a USB port below, the raised wire contacts inside the port could cause chenille fibers to become stuck to them (and indeed that happened to me recently).

enter image description here

According to Wikipedia, chenille can be made from cotton, acrylic, rayon or olefin. A couple of resources I found said that those materials are all electrically conductive to some degree:

  • cotton is "slightly conductive"1
  • acrylic has "fair to good" electrical conductivity2
  • rayon has "fair" electrical conductivity2
  • olefin has "excellent" electrical conductivity2

So if a chenille fiber got stuck inside a USB port, could that cause any problems with the operation of the port (such as by creating an electrical short if the fiber touched 2 of the wire contacts)?

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  • \$\begingroup\$ Do you have any actual problem with the port, or just asking theoretically? If you have a problem, please describe it. Is it not working at all, or the connection is intermittent, or unreliable? \$\endgroup\$ – Ale..chenski Sep 16 '17 at 21:37
  • \$\begingroup\$ @AliChen I am asking theoretically, as I have not used any of the ports since cleaning them. \$\endgroup\$ – pacoverflow Sep 16 '17 at 21:38
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    \$\begingroup\$ 1. The wire in the pipe cleaner could damage the contacts. 2. A piece of fuzz would be more likely to prevent a good connection between contacts that are supposed to connect than to cause a short. \$\endgroup\$ – JRE Sep 16 '17 at 21:42
  • \$\begingroup\$ The one actual somewhat Scientific source you link clearly identifies these resources talk about TriboElectric properties. They have nothing to do with the actual conduction of low potential currents. Else we'd all be in a lot of trouble with our PVC, Polyolefin and ABS wrappings to plugs, plug sockets and cables. \$\endgroup\$ – Asmyldof Sep 16 '17 at 22:04
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    \$\begingroup\$ Step one in being serious in engineering is to never look at material properties in a book that talks about safe ironing temperatures. That's my new motto now. \$\endgroup\$ – Asmyldof Sep 16 '17 at 22:08
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While some polymers can be somewhat conductive (that's how some organic devices work), those fibers you mentioned cannot be considered conductive: sweat, for instance, is orders of magnitude more conductive.

Instead, the problem is that those fibers are actually insulators, and therefore they will prevent a good contact between the two connectors. The contact surface will decrease and thus the contact resistance will increase. If such contacts are supposed to carry a large current (i.e. the power contacts), such increased resistance might induce eccessive voltage drop or even local overheating.

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