Building an artificial heart with ferrofluids

Here’s something we thought we’d never see on Hackaday. [Chris Suprock] is developing an artificial heart he calls Steel Heart. It’s an artificial heart powered by electromagnets and ferrofluids.

The idea behind [Chris]‘ artificial heart is ingenious in its simplicity. An elastic membrane is stretched across a frame and a magnetic liquid (or ferrofluid, if you prefer) is poured across the membrane. An electromagnet is activated and the membrane stretches out, simulating the beating of a heart. Put a few of these together and you’ve got a compact, biologically inert pump that’s perfect for replacing an aging ticker.

[Chris]‘ plan to use ferrofluids and electromagnets as an artificial heart give us pause to actually think about what he’s done here. Previously, artificial hearts used either pneumatics or motors to pump blood throughout the body. Pneumatic pumps required plastic tubes coming out of the body – not a satisfactory long-term solution. Motor-driven pumps can rupture red blood cells leading to hemolysis. Using ferrofluids and an elastic membrane allows for the best of both worlds – undamaged blood cells and transdermal induction charging.

Not only is [Chris] designing a freaking artificial heart, he also came up with a useful application of ferrofluids. We were nearly ready to write off magnetic particles suspended in a liquid as a cool science toy or artistic inspiration. You can check out [Chris]‘ indiegogo video with a demo of the ferrofluid pump in action after the break.

59 thoughts on “Building an artificial heart with ferrofluids

    1. By what i got out of it, the fluids are in a sealed chamber that is used to pump the blood. The ferrofluids shouldn’t come in contact with the person unless a chamber ruptures.

      1. Doesn’t matter. The whetting agent doesn’t keep the colloidal suspension of particles afloat for long in the presence of large (or even moderate) magnetic fields (especially when they’re fluctuating). Eventually, the particles start to ‘clump’ and the fluid looses it’s properties..

        .. not that this isn’t a great application. ;)

    2. @steve: I think you’ll find that the ferrofluid will not be in contact with the human tissue itself, but instead be contained separately.

    3. It’s also using an electromagnet to movie a liquid that is mostly iron.. I’m pretty sure it effects cell growth too do to emissions of energy in a low-capacitive enclosure apposed to a poly based encasing that is biologically compatible with anti-bodies.

      But hey, if all these microwave devices can just “metabolized more glucose” so can this heart pump plasma without any effect, even though staggering evidence suggests otherwise..

      1. If by “liquid that is mostly iron” you mean blood then you may be over-simplifying things. Blood does have a large amount of iron atoms in it (not “mostly iron” but I’ll give you a little exaggeration) but it is not ferromagnetic metallic iron(0) (the kind found in steel) but probably iron(II) (iron with 2 positive charges), which is diamagnetic (not magnetic). Haemoglobin itself, as a molecule, is most certainly non-magnetic, experimental observations have shown this. In other words, blood is not significantly affected by magnetic fields.
        You should also consider that, if magnetic fields were a problem, the magnets within motors in existing artificial hearts would be problematic.

        1. @chiralspiral

          Lets not forget all the anecdotal evidence we have: MRI’s do not in fact rip all the blood from your body.

      2. I like how I’m accused of “over-simplifying” things based on a grade school biology perspective on medical science, and a irrelevant over-exaggeration of my criticism. Typical HaD responses..

        Both of you obviously don’t know what the sub-molecular structures of everything are made. Learn that then claim magnetism ‘has no effect on blood’. Based on that understanding RF and green house gasses have no effects on the poles and fields of earth; you must be the scientists governments pay to do enviromental research around commercial interests XD..

        Oh yeah..the brain cortex cells hold state based on blood infusion.. the blood which has no capacitance..

      3. I am acutely aware of the sub-molecular and indeed sub-atomic structures of both iron and haemoglobin. You are correct that sub atomic particles are indeed affected by magnetic fields but this is not really true of all atoms.
        If you want me to go into more detail here goes:
        The reason that the iron in haemoglobin is not significantly affected by magnetic fields is because all of the electrons in the orbitals of the iron are paired. Iron(II) is probably the oxidation state of the iron in blood and it has 6 d electrons. These can exist in 5 different orbitals, (each capable of holding 2 electrons) three of which are slightly lower in energy than the others. The iron in haemoglobin is most probably “low spin” iron II, meaning that the 6 d electrons sit in the three lowest energy orbitals and are all paired (in other words the energy required to pair the electrons is lower than that required for them to exist in the higher energy orbitals). The paired electrons all have opposing spin magnetic moment and so the action of a magnetic field on one electron is cancelled out by the action of the same magnetic field on the other in the same orbital. Of course it is still true that the nucleus of an atom is affected by magnetic fields (this is the basis of MRI scans) but this is a very low energy effect, as illustrated by the huge magnets required by MRI machines just to induce an energy difference with the energy of radio waves.

  1. Wow. Those guys are serious. I went to their site for more info and found out they like everything by the looks of it.

    Throw in their wireless powersupply on their site and you have a great system.

    1. No, you don’t. As I said: the ferrofluid is not long term stable and loses its properties. Also there is the danger of membrane damage in which case the toxic mineral oil will be leaked into the body with fatal consequences. An also, I don’t see, why the ferrofluid can not be substituted with a simple magnet attached to the membrane.
      I also guess that the power consumption of this system is way to high.

      1. If it ruptures and stops working and leaks into the body, then you have the same problem a normal heart would have when it ruptures :P

  2. I’d never imagine that the plan would be to have them exposed to human body conditions, risk of washing away even… but yeah, as I recall, the sutfactants that keep the magnetic material from clumping will break down, although, at last I’ve seen, and artificial heart is only considered a stopgap measure until a specially designed “non-artificial” heart can be found for the patient.
    We can’t make you better, faster, or stronger;
    We don’t have the te hnology

  3. bar the stability issues menitoned above i think this looks very promising,

    perhaps a liquid suspension isnt needed as such, if one could coat the membrane in a flexible magnetic material it could remove the issue while providing a similar compact pumping action.

  4. Okay, wasn’t familiar with ferrofluids and the clumping. What about the ferrofluids being replaced every month, year, years… or whatever? If you had two tubes to the surface of the skin, you could “flush” the system. I would much rather “flush” a system then replace the heart.

  5. This is a really bad idea.

    What would proximity to a 50Hz transformer, a mobile phone or the EM fields in a car do to this

    People with pacemakers died when they got too close to microwave ovens even when they added the extra shielding they still have to be careful

  6. To deal with the clumping issues, maybe they could separate the fluid in smaller chambers, or use pellets embedded in one membrane instead of a ferrofluid between two. Also, a torn membrane releasing oil and filings into the bloodstream wouldn’t be too nice XD

  7. Can someone confirm the validity of this… Isn’t blood (or some of its components) affected by artificially-created (man-made) magnetic fields?

    1. Bingo! I guess that small pieces of metal or neodyme sewed to the flexible mesh or even composite material made from small magnetic particles in some kind of rubber would be much better.

  8. Well you could use ferrocylicone blend insted of a pure ferrofluid that would solve the clumping problem. and would most likely make bonding between the active an inner portions of the device much more reliable.

    The main thing i’m looking at here is how are they going to deliver the magnetic pulse to the device.

    if external to the skin you have that whole drop off of effect to the square of the distince of the field.

    Allthough an internal set of coils might suffice

    you’d think that we’d be pusing to get the printed/labgrown hearts out faster.

    i havent heard much on the development for that in a while.

    Alternetly. This could be used as a much more reliabul system for stopgap mesures in hospital.

    short term external to the body maby as a long use bypas (heart lung bypas michines dont work for verry long)

  9. A problem with elastic materials in this application may be fatigue resistance. Bend a wire too far, bend it back a few times and it snaps. Bend it a little bit and it still eventually breaks but it takes a lot longer. Leaking ferrofluids into the bloodstream would be bad. Love the idea – figure out solutions to problems like this and it might just work.

  10. I know I’m late to the conversation, and very much less informed if the comments posted are any indication, but why can’t a gel or flexible plastic be used as a more stable suspension to avoid clumping and still get the same muscle-like feel/quality…. though, I’m sure the ferrofluid is gelled, but are there not latex fabrics which could have many of the same properties as a fluid, while avoiding unwanted movement (at least in the short term)?

  11. Wouldn’t a small sealed internal turbine with an inductive rechargeable battery be smaller and more efficient? Like a submersible pump in miniature? Or is the plan to create something with a heart beat?

    1. Turbines, from what I’ve read on the subject, are a satisfactory short-term solution. But, in addition to hemolysis, the blood vessels themselves were designed/have evolved for heart beats and backflow prevention.

      1. I stand corrected — turbines do seem to be the way to go.

        And, if the following quote is indeed true, I’ll want one of these someday if I ever get heart disease:

        “One of the most surprising things about the LVAD is that it does something the medical community had thought impossible: It reverses heart failure. Until the past few years, damage to the heart was thought to be permanent. But it seems that by relieving strain, an LVAD lets some hearts damaged by, for instance, heart attacks repair wall tissue and grow healthy again. Often the LVAD can be removed. “It’s like putting a cast on a broken ankle,” Cohn says. “You take it off when it’s healed. We had no idea that could happen.””

      2. Also the flow of lymph fluid through the lymphatic system is helped by a heartbeat (other contributing factors is the contraction of smooth and skeletal muscles). In older patients who don’t exercise much, this MAY be a problem?

      3. no. its been proven that we can live without a heartbeat and their are people currently living without one. the idea that a heartbeat was necessary for such functions was an assumption because it made sense. in reality theirs no need for its just that a heart was the only way nature could create a good pump.

  12. So frustrating.

    I’ve got a bottle of ferrofluid on top of my refrigerator and a latex animal balloon inside a plastic pipe wrapped in copper under my sink.

    I was like 3 days away from “first to blog cred” on this topic.

    Not to be cliche, congratulations are due to the victor. I don’t believe you can own an idea, and I was obviously a little too slow.

    Potential aplication:
    I was developing it as quiet propulsion for underwater/surface vehicles. Was gonna pimp it to the ONR if it worked and was efficient enough.

    1. That is an application on a completely different scale than the heart pump, and a production unit would be a completely different than what they’re doing. Go for it.

  13. Im surprised that all the concern was about ferrofluid toxicity and not the immediate threat of heart failure without the pumping effect of the fluid gone.

    By the way, great idea.

  14. I must admit I am a bit amused by the assertions that ferrofluid is unstable and would not be able to perform in conditions such as those found in the human body. The temperature constant is not worth mentioning, and as it will not come in contact with body tissues or blood there is no concern about toxicity. Indeed even if they did, some ferrofluids are being used in experiments as MRI contrast media with great success and these fluids are not a danger. Ferrotec has been manufacturing ferrofluids for 45 years and these products are used in critical applications throughout the world every day. Audio loudspeakers, with their intense magnetic fields and high operating temperatures do not cause the fluid to separate or break down because of the tremendous colloid stability inherent in these fluids. These speakers function for many years with no appreciable loss of stability and no deleterious increase in viscosity. Ferrofluids are an integral part of the seals required in equipment used to produce microprocessors and computer chips by the millions. I’m sure that these chip manufacturers would be very unhappy to hear that ferrofluids are unstable and prone to clumping.
    I think what our critics here are alluding to is the ferrofluid produced using printer toner and vegetable oil, or perhaps the kitchen chemistry version that is so often seen on YouTube. Do a little more research and you will find that we have come a long way from the Dark Ages. If interested in reality, please explore our web pages and contact me through our online resources.

  15. Using ferro fluids is too risky due to Murphy’s law and it could leak.. however this could easily be substituted by a Membrane with ferromagnetic powder or particles cast into the membrane itself.. therefore magnetizing the membrane and not an intermediate layer in between. I recently read an article about pumps that were used to aid failing hearts. The speculation is that they can be used long term. There have been patients using them for a reported 8 months without problem. The issue with pumps is that the lymphatic system requires a beating heart to move lymph, however there hasn’t been side effects thus far.

    Lastly, I would like to add that there is a lot of doubters here who don’t realize that this device is built for extremely dire situations usually in elderly patients. It doesn’t need to last 20 years. Most people who have a device like this installed wouldn’t have lasted 6 months. I think getting 5-10 years out of a device like this shouldn’t be a problem. “Harmful magnetic waves” and the such really shouldn’t even be factored in. The person will be dead before they even see side effects.

  16. I love that the scientists from the popular science article equate artificial hearts that pump to when people would try to make flying machines with flapping wings. Kind of seems dumb now. Everyone who has worked on artificial hearts before must have all given themselves huge face palms. I would have.

  17. Interesting work, it might also be feasible to use multiple small versions of this distributed throughout the body to act as “relay stations” to keep the blood pressure high and prevent pooling in lower extremities.
    Power the whole system with induction but also use miniature axial ultracapacitors as a backup as these can last for decades without degradation.

    1. Fascinating idea! Radio signal repeaters have been used successfully for decades, why not a series of circulatory repeaters, especially in the lower extremities, to help pump blood back to the body core? Might help alleviate conditions due to poor circulation in diabetics and para/quadriplegics.

  18. The use of ferrofluid kind of seems redundant when you can just use magnets embedded into some kind of flexible membrane. I’d like to know where the power for the electromagnets would be coming from though.

  19. Why one membrane when dozens in parallel could be used separated by flat sheets of plastic?

    Thinks countercurrent multiplier here.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s