Curved magnet edges
  • FullDiverFullDiver March 16
    So I've read that coating failure is most common on the edges due to the coating not being distributed evenly on them, but you can't just eliminate the edges. Can you at least dial back the edges by making them more rounded instead of the 90° drop that we normally have, or would it not be beneficial?

  • CassoxCassox March 16
    Yeah, I got a big batch of mags that were tumbled. The edge are way better but I haven't gotten them coated yet.
  • JupiterJupiter March 22
    On a slightly unrelated note, I'd be curious to know if anyone's experimented with "plate" magnets. (My term, just made it up, might already be a different term for what I'm talking about and "plate" may refer to something else.)

    I mean, like, a wider than typical magnet that's no thicker than a dime after coating. I imagine such a thing must be possible, structurally, basically my thought is that current magnets are still relatively thick considering they're often implanted in thin locations in the body, fingertips for instance.
  • Wouldn't ' that give really sharp edges that makes it esp. prone to corrosion?
  • ChrisBotChrisBot March 24
    @Jupiter, that's actually a very interesting concept!
  • ZerbulaZerbula March 24
    First immediate issue is with surface area impeding blood circulation, too large of an implant, even if thin, still starts cutting transport ways. X_x

    It's one of the reasons that larger magnets become more difficult.

    Not saying impossible, but food for thought depending on placement location. ^^
  • JupiterJupiter March 26
    Unless it was contoured to fit each person, my suggestion wouldn't be for finger tip placement.

    Blood circulation is important I suppose...

    New idea... skin that doesn't need a continuous blood supply!
    Any thoughts on that one? Mine all involve advanced robotics.

    (That was a rhetorical question, no need to answer.)
  • I am actually wondering about that: I recall looking through the cavaders and from textbooks, and nowhere have I found that every micron of skin would have blood vessels going up from the muscles which is what everyone here seem to think happens. In fact, if that's the case every time we pinch out skin there would be massive bruising since we're pulling the skin away from the structures underneath and would be tearing blood vessels should there be any vascular connection.

    I have a feeling that while there are some blood vessels that enter the skin for blood supply, but those entrances are entering a network of blood vessels that travel along the surface of the skin. So as long as the implant stays under such network and not cut through the entrance points, it should be fine.

    Question would be how dense are those entrance points. Will be doing the skin module after a couple of weeks. Keep you posted.
  • ZerbulaZerbula March 26
    I wouldn't say every micron of skin, but capillaries in the fingers do tend to be numerous, no?

    And while every cell doesn't have direct contact to a blood source, doesn't that mean cells need to rely on one another or have those nutrients and oxygen somehow move among the cells? X_x

    I think the roadblock comes in when you divide material, not that it's necessary cutting off veins directly, but simply interrupting transmission of needed resources.

    I don't know enough about the body, other than this is my guess. Correct or validate me please. ^^'
  • Technically yes, but consider that 1) skin is actually quite thick and it is possible for nutrients to transport horizontally parallel to the surface of the skin and 2) while there are many capillaries in theory in practice they can run horizontally parallel to the surface of the skin.

    In both scenarios the pathway does not run perpendicularly to the skin surface except for specific places. There has to be a reason why we don't tear apart capillaries to the skin every time we pinch our skin, say on the back of the palm, and that's what should happen if the skin just relies on capillaries that run vertically from muscles to skin (and also, every time the skin the stretched, so pretty much every time we move as well).

  • ZerbulaZerbula March 27
    True true. Just trying to help. ^^ thank you @IvoTheSquare
  • misslittymisslitty March 27
    @IvoTheSquare You're right, I'm pretty sure 150 um any direction and you would contact some form of vasculature.  That's not to say it can't be done, but you would no doubt have some extent of foreign body response.  I think I've posted this somewhere before, but like you said you have a deep network (plexus) of vasculature that leads to more superficial veins.image
  • Actually, I should also point out that while I did say that skin is quite thick it would depend on the location. I'm not quite sure how thick the skin on fingertips are (though considering the size of the finger how big can the magnetic sheet can get anyway?).

    Also, first time that I've seen a diagram of skin layers with vasculature going down through the adipose layer with that kind of density. Usually the plexus is between the hypodermis and recticular dermis (Anyway, will learn this properly in a couple weeks time!).
  • Ok, now that I've done the skin module (which turns out to be quite useless for this) and done some research I think I have a better understanding of skin vasculature.

    It appears that the whole skin (epidermis, dermis and the subcutaneous layer) as all supplied by what they call perforating branches. These are large vessels including both arteries and veins and comes out of the middle of muscles (and sometimes the edges of muscles i think). In fact, plastic surgeons have a technique where they cut out the skin, rotate it around the perforator, and sew it back on to close wounds etc. There is a very good article about it here, plus nice pictures of the perforator when the flaps are cut: https://www.researchgate.net/profile/Sandeep_Sebastin/publication/51048162_Clinical_Applications_of_Perforator-Based_Propeller_Flaps_in_Upper_Limb_Soft_Tissue_Reconstruction/links/5645455e08ae451880a8c43f/Clinical-Applications-of-Perforator-Based-Propeller-Flaps-in-Upper-Limb-Soft-Tissue-Reconstruction.pdf

    These flaps can get really huge, which means that these perforators are pretty far apart depending on the location (would be much closer, say, for the skin on the back of my finger than the skin on my forearm), so basically, a flat implant placed underneath the subcutaneous theoretically should be able to get quite big before the perforators start getting in the way.

    However, this is not going to be easy as we are now talking about placing implants on the deep fascia and pretty much right on the muscle (and builging muscles might cause problems). More problematic would be that we might need to cut out a whole section of skin to find the perforator in order to put an implant in - no easy task.
  • misslittymisslitty April 15
    That article was pretty incredible, could have big implications
  • ZerbulaZerbula April 18
    Yay provoking thought! :D

    I wish I was more useful... lol ;_;
  • I haven't gone out looking yet, but do you think ultrasound imaging could be used to find the perforator before any cutting happens?

    That's a super exciting paper! I can't wait to see what we do with this. I may perform the dark arts on the undying armor thread once more, because this could be solve the circulation issues that have been plaguing development. 
  • I somewhat doubt that. I think our current ultrasound resolution is a bit too low. And from memory there is another paper that discusses looking at the perforator vessels using dye.