Hello all, newbie here.
Anyone got any experience of what Pt100 RTD to use for measuring temperature when doing KOH etching of Si?
I've looked into it and it seems a stainless steel sheath is a bad idea as KOH attacks it leaving the solution contaminated. Should I go for some kind of ceramic alternative?
A number of materials hold interesting properties not constrained in many ways. Ceramics are very brittle in most situations which limits practical applications. There are ways this can be greatly mitigated. One involves the mixture as in diffused through out, and/or layed in a "sand which" way of certain organic and/or inorganic materials. One way is to use a certain material in a directed and diffused like manner. This involves construction on a microscopic level of a "false" crystal structure,(thats how can split the hardest natural substance, target its weakest point), in some applications. Crystal will fracture alone the structural pattern of same, and given a focused impact will, with other materials spread out in three dimensions, if one looks at the concussion of such as HEAT (high explosive antitank) rounds. This would incorporate inorganic as well organic polymers ideally diffused through out the ceramic . Chobban armor, developed by the British and improved by the U.S, uses a formula that employs a lot of materials designed to defeat any type of antitank shell. At least that in open source. C. armor has been in the hands a long time ago of the Russians. The west improved on the original material quite a bit. (Said armor is used on tanks as far as I know and other things, but as far as I know first applied to tanks). But all takes to destroy just about any thing is build a bigger bomb, with the ideal to direct the blast at the target. Raw ceramics for the most are not that heavy but a tank is REALLY HEAVY). You can change many ceramics, some are very heavy, but density and/or dissipation of kinetic force is done in way that gives a target or otherwise any armor This acts likes the "crumple zone" of your car, forward of the cabin. This dissipates kinetic force by displacement of impact energy.
Pure density also used is applied to resist impact by brute force. The Russians started using a variant of C. armor at least with the T-90 tank, by no means their latest. I cant go into just how what is Russian armor now, this would reveal the holy of hollies of intelligence, sources and methods. And for obvious reasons, I can't describe how our armor is designed. Also another way, also public knowledge is to cover a tank with "reactive" armor. This in effect dissipates a shells impact by literally exploding, taking a lot of the kinetic impact away from said tank. My sources tell me Israel developed reactive armor at first for a very simple reason; its a hell of a lot cheaper then a lot of of the materials we use. We also use as do the Russians and others reactive armor.
Use of stainless steel or any thing else can be "dealt with" by use of chemistry and better, use of chemistry with use of energy beams to accelerate materials seperation. This means seperation if not breakdown in and of itself, materials in a target. In the case of stainless steel, we have steel and chromium. Why do this? If you seperate say chromium from steel, you can then target one/or both much more effectively. But all materials are vulnerable to "something". depends on what on what do with a material.
My personal prejudice is an interesting number of polymers; tetrathiaphulverine, tetrathyaphynaline, for example. (My spelling is really so bad I spelled each phoneticly) You can exlore inorganic/organic materials and even produce a combinatio by using simple, desk top bath ultra-sound tank. The kind used to clean jewlery for example. The effect of Usound is to produce micro-spheres of cavitation. micro-cav is the creation of intense spherial shockwaves that cause great heat at a microscopic level. This also creates as the energy of the bubble must go some where a very small but powerfull shockwave. This can in effect create a resonance effect, or effect that "hums along" at the same reinforcing frequency, a harmonic We have used explosives that forge a composite for much larger materials. Semi-conductors are a good area to look at, I've worked trying to design, manufactore economicly oranic semiconductors, and just plain conductors. Both ceramics and silicon have some similarites, but by no means are they the same. I went into "war and peace" concerning armor, for example to provide a bit of insight of my knowledge only of this area. My company is actively exploring better p.v. solar cells, including transparent solar cells for windows as a coating. They use only the nonvisable light spectrum to tap into the sun for power for example. Even a small degree of effeciency, if cheap enough would give us tremendous power we would think we could never get.
Another example I find really neat is using the very unique properties of the is use of certain polymer based electronics to take the place of circuits themselves, at first in limited ways. Some enginered polymers are anistropic for example, conducting electricity or focus of em forces, in one direction only. Thats errie, but then you can use circuits for things the early electronic materials can not.