05/07/2016 at 03:13 •
You can see the copper creeping around the coil, it is the white colored stuff over the black.
This setup takes about 20 minutes to completely plate a muscle, whereas it took days before.
The electrolyte is copper sulfate and h2so4 with a copper pipe that the muscles are wrapped around to stretch them out allowing plating between coils. The copper pipe goes to the negative terminal.
The positive terminal is just some copper foil.
The 8-track player box was repurposed to house my 3d printed stir plate contraption thingy.
A stir bar was made using a piece of ptfe tubing a neodymium magnet and some silicone.
The voltage reads zero for some reason but current set to 100 mA and voltage set to .9 volts before hooking it up works the best.
03/22/2016 at 00:13 •
The graveyard of failed muscles grows daily.
What I have learned is that sanding the line before twisting with 400 or 600 grit sandpaper vastly improves the adhesion and toughness of the conductive coating.
Silver may not be necessary Nickel powder seems to have the same resistance when used with a polyurethane binder.
Graphene sucks and is highly overrated it generally is much to resistive to be used in this application.
Homochiral and heterochiral twists are pretty much uncontrollable with this 150lb test, I may have to switch back to the 80lb test for the prosthetic hand as it seems to work so much better.
A different twist morphology can give less power but longer actuation distance and may be the way to go for a prosthetic hand. I discovered this by accident as twisting these things only goes correct about 75% percent of the time and the other 25% you get side coils. However these side coils can be made on purpose and when given a quaternary twist pattern actually have a longer retraction distance and can be made conductive much more easily as there is more surface area.
I will be focusing on anything goes for the 2016 HAD prize for this small project as I am 99% of the way there. I also need this to work very well for the final HAD prize segment of assistive technologies.