Spider silk conducts heat as well as metals, study finds
Thermally-conductive electrical insulation?
Spider silk conducts heat as well as metals, study finds
I've downloaded a couple of papers on the method used to measure this phenomenon, and may try to do it myself. This sounds fascinating.
Now, let's see, where can I find a garden spider? We used to have one spinning webs on the house every spring. Ours would take the web in every evening and spin a new one in the morning, so it probably does little harm to harvest a web in the evening.
For those interested in the nitty-gritty of the technique, I found a paper on-line under the file name adma_201104668_sm_suppl.pdf. The method is intended for thin conductive wires and involves stretching a wire between two good heat sinks. The wire is self-heated by a DC current, and temperature change is evaluated by the resistance change. To test spider silk, they sputter-coat on about 10 nm of gold (the apparatus for this is common in electron microscope labs, and the paper reports using SEM on samples of spider silk). Sputter-coating can be rigged by any fusion experimenter with a modest vacuum system. The test is done in a vacuum, somewhat better than my present capability, but I was hoping to go turbo anyway. They aim for < 1 millitorr (below the range where thermocouple gages work and so below significant convective heat loss).
The electronic apparatus involved seems to be a fast-switched current source and a digital oscilloscope. Type T thermocouples (suitable for vacuum and good at near-ambient) are used for temperature measurements of the heat sinks.
I'm wondering if my thermal imager can see something this thin. Mine is not intended for close focussing, but I think there are models that work on microscopes. If so, this test might also be done by viewing thermal gradients directly. I'm also interested in using a fine thermocouple as a heat flow gage, allowing direct measurement of heat flow down a filament.
Now, let's see, where can I find a garden spider? We used to have one spinning webs on the house every spring. Ours would take the web in every evening and spin a new one in the morning, so it probably does little harm to harvest a web in the evening.
For those interested in the nitty-gritty of the technique, I found a paper on-line under the file name adma_201104668_sm_suppl.pdf. The method is intended for thin conductive wires and involves stretching a wire between two good heat sinks. The wire is self-heated by a DC current, and temperature change is evaluated by the resistance change. To test spider silk, they sputter-coat on about 10 nm of gold (the apparatus for this is common in electron microscope labs, and the paper reports using SEM on samples of spider silk). Sputter-coating can be rigged by any fusion experimenter with a modest vacuum system. The test is done in a vacuum, somewhat better than my present capability, but I was hoping to go turbo anyway. They aim for < 1 millitorr (below the range where thermocouple gages work and so below significant convective heat loss).
The electronic apparatus involved seems to be a fast-switched current source and a digital oscilloscope. Type T thermocouples (suitable for vacuum and good at near-ambient) are used for temperature measurements of the heat sinks.
I'm wondering if my thermal imager can see something this thin. Mine is not intended for close focussing, but I think there are models that work on microscopes. If so, this test might also be done by viewing thermal gradients directly. I'm also interested in using a fine thermocouple as a heat flow gage, allowing direct measurement of heat flow down a filament.