Entry 2 Addendum

Further Ideas

While I'm excited to observe the effects of tri-nested coils on MR Fluid, the original intent was to craete something that could be used for haptics. Even if that doesn't pan out, identifying the tri-coil effects on MR Fluid (if any) will be worth the effort.

I had a second idea though, another related experiment to run. There are other non-newtonian fluids besides just MR fluid, all of which exhibit different properties. I need to look at the exact numbers, but I'm fairly certain that the cornstarch-water mixture commonly "oobleck" has far greater sheer thickening potential than standard MR fluid. The problem being that it's not controllable via magnets and only thickens with sudden impact - and even continued pressure does not maintain this high viscosity state.

There are some interesting videos online in which oobleck is placed directly on a speaker cone. when powerful low frequency sound is played is causes the fluid to thicken. if one then prods the fluid a bit it will end up "dancing" - chaotically changing shape in response to the fluctuating vibrations of the sound waves.

My thought is this: Would adding magnetic particals to oobleck fluid and using a tri-coil magent to oscillate the particals at a low frequency produce stable sheer thickening? If so, this could present a controlable fluid with a much higher viscosity capability than standard MR Fluid.

Since the tri-coils can dynamicall produce magnetic fields in 3 perpendicular dimensions, it may be possible to force the iron particals to oscillate between aligning vertically and horizontally - hopefully producing enough sheer force to significantly thicken the fluid. My conern is that since the particals are spheres alternating magnetic fields won't move them in a way that generates enough friction to achieve this.

What excites me now is a new paper I just came across. While looking into MR fluid composition and the effects of iron oxide vs carbonyl iron, I unexcpectedly wondered if graphite could make an MR Fluid. while trying to research this I came across a paper in which researchers were able to use magnetic fields to control and move graphitic microparticles in aqueous solutions. These were actually graphite microflakes. This excites me because I think the non-spherical shape will allow the changing magnetic fields to truly re-orient the flaks, and that the irregular surface area of the flakes will produce more friction.

Additionally, even if the fields aren't able to rotate the flakes, the researchers were able to move them through the solution using magnetic fields. That may be even better at generating the needed sheer force.

Of course, I'm a long ways from testing this out. I feel like I need to first complete my assesment of tri-coils on traditional MR fluid.