The Naked Scientists

The Naked Scientists Forum

Author Topic: Need advice for a magnetic art installation  (Read 2923 times)

Offline Toni Giddings

  • First timers
  • *
  • Posts: 1
    • View Profile
Need advice for a magnetic art installation
« on: 13/08/2013 17:27:13 »
Hello,

I am creating an art installation for the V&A and not quite sure how to go about producing it scientifically.

The idea is that the word magnetic, made from iron, in my typography will be attached to a magnetic circuit which can be turned on and off.  It will be in a concealed box, run on battery power and there will be metal filings also in the box.  They will create the illusion and will magically unveil the font when turned on, making the design visible.

I am considering getting the letters cut out of iron individually and each letter placed on a cylinder that connects each font to a slab of iron to hold all letters together, 10cm away so it can be hidden behind card. I can the wrap each cylinder with wire so it conducts the current and possibly have a battery per letter to connect them.

This may not work, i need your advice!  Also, I am not sure how to create the switch option and which metals will be best for this.  I heard size and shape make a difference when conducting a field, if this is the case i can send measurements.

All the best,

Toni
« Last Edit: 13/08/2013 17:29:54 by Toni Giddings »


 

Offline RD

  • Neilep Level Member
  • ******
  • Posts: 8128
  • Thanked: 53 times
    • View Profile
Re: Need advice for a magnetic art installation
« Reply #1 on: 13/08/2013 23:40:07 »
If the sign is vertical the iron filings will fall down when the electromagnet is disconnected, and won’t jump back up again when it is connected.

NB: iron filings are a hazard, they could get in eyes or be inhaled.
 
There is a material called Magnetic-field viewing-film which has nickel particles suspended in it , which avoids the “won’t jump back up” problem …
https://en.wikipedia.org/wiki/Magnetic_field_viewing_film
https://www.google.co.uk/images?q=Magnetic+field+viewing+film

However, like ye-olde video/audio tape, the magnetic viewing film retains the pattern even when the magnetic field is switched off. 

There is magnetic liquid called Ferrofluid … https://en.wikipedia.org/wiki/Ferrofluid
[:0]

Which is iron powder in mineral oil (like engine sump oil) which stinks and which will stain everything it touches brown.

If your sign was horizontal, a shallow [covered] tank of Ferrofluid ,  with magnetic letters below the tank, letters would appear in the surface of the liquid, hopefully with pointy bits …


https://en.wikipedia.org/wiki/File:Ferrofluid_in_magnetic_field.jpg

If the layer of ferrofluid was very shallow [it's expensive] say 3mm , the ferrofluid will creep towards the letters leaving a bare, but brown-stained, background. When the magnetic letters are removed from below the tank the ferrofluid will flow back to cover the bottom of the tank.

Strong [rare earth] permanent magnets attached to the [back of] iron letters may be a better option to an electromagnet. Moving the iron letters away from the tank would make the pattern in surface of the liquid disappear.

A vertical ferrofluid sign may be possible using a suspension of oily ferrofluid in [sugar] water ... http://www.lbl.gov/Science-Articles/Archive/ferrofluids.html  but standard ferrofluid will stain a [fish?] tank brown making it somewhat difficult to see through. 
« Last Edit: 14/08/2013 03:38:52 by RD »
 

Offline evan_au

  • Neilep Level Member
  • ******
  • Posts: 4105
  • Thanked: 245 times
    • View Profile
Re: Need advice for a magnetic art installation
« Reply #2 on: 14/08/2013 11:33:01 »
Some random discussion-starters:

How much interaction do you want between the viewer and the artwork?
  • Fully autonomous, with no user interaction? (A motor can move magnets in fixed patterns, out of sight.)
  • Fully interactive, with the users sprinkling magnetic filings and moving magnets around to make the filings do "tricks"?
  • Press a button to make the letters appear/disappear? (Digital: On/off)
  • Pull a lever to make the letters appear/disappear? (Analogue: partially on/off)
  • Twist a wheel to make the letters spin around?
Having seen ferrofluid, its bizarre, hedgehog appearance is an attention-grabber. It is best if you can continuously vary the strength of the magnetic field by moving a magnet under the ferrofluid so it can get closer or further away. Do some experiments with iron letters and strong magnets.

You could also use magnetism to illustrate transferring rotation through a glass wall using magnets. Have a clear plastic wheel on the outside of the glass, with a bar magnet close to the glass. You can rotate a similar bar magnet inside the glass, with no mechanical connection between them.

Electricity and magnetism are intimately linked, and you can make backto-back LEDs flash on and off by moving a magnet close to a coil of wire.

Another demonstration I have seen uses an "old-fashioned" colour TV/computer screen with a cathode-ray tube (not the newer "flat-panel" LCD screens!). You could display the word "Magnetism" on the screen, and then let people move a strong magnet across the front and sides of the TV screen, which twists and distorts the shape and colours of the image on the screen. You need to ensure that the screen has a plastic shield, otherwise someone may smash the magnet into the screen!

Electromagnets draw a lot of current, and batteries tend to run out very quickly - and are a nuisance to replace.
  • Permanent magnets don't have this problem, but they are always "on". You can move them close/distant.
  • If you want to use electromagnets (so they can be switched on & off) it would be better to use a transformer to produce low-voltage current to power the electromagnets. Make sure that there is no way people can come near the electrical voltage (get an electrician to help you). 
For user protection:
  • Users should not be able to touch ferrofluid
  • Supervision may be required if children are to sprinkle iron filings.
  • People with heart pacemakers should stay away from strong magnetic fields (permanent magnets are used to temporarily disable a malfunctioning pacemaker).
  • You could put the artwork in a glass/plastic case, with wires or rods passing into the enclosure. 
« Last Edit: 14/08/2013 11:36:56 by evan_au »
 

Offline RD

  • Neilep Level Member
  • ******
  • Posts: 8128
  • Thanked: 53 times
    • View Profile
Re: Need advice for a magnetic art installation
« Reply #3 on: 14/08/2013 22:41:30 »
The nickel-in-oil, ferrofluid as used in magnetic viewing film, wouldn't create a brown rusty mess (no iron).
If mixed with sugar-water to match the density of the nickel-laden-oil , it would behave like the iron filings, but without the annoying "fall down" problem due to gravity : the blobs of oil would have neutral boyancy [ lava-lamp-ish ].

Another idea* ...

Spell out the word MAGNETISM using bolts, or bits of threaded bar and nuts, to form the letters
Use the coarsest thread you can find.

Mount [weld?] the letters on an iron plinth [more threaded bar ?]

Sit this iron sculpture in a 1cm deep bath of regular rusty brown Ferrofluid , [ a shallow thin plastic tray ].

Place iron sculpture in tray of Ferrofluid in a fish-tank  [seal the tank lid to contain the stench and prevent people from touching the oily fluid which will stain clothing ]

Apply a varying magnetic field from below : the Ferrofluid should crawl over the MAGNETISM letters if the magnetic field is strong enough, ( I strongly suspect battery-power won’t be sufficient , I believe a heavy-duty high-current power-supply will be required ).

[ * never actually tried this , just brainstorming ]
« Last Edit: 16/08/2013 01:07:57 by RD »
 

Offline evan_au

  • Neilep Level Member
  • ******
  • Posts: 4105
  • Thanked: 245 times
    • View Profile
Re: Need advice for a magnetic art installation
« Reply #4 on: 15/08/2013 23:17:16 »
More Brainstorming: One way to demonstrate random/chaotic/interesting motion with a magnet is:
  • Suspend a magnet on a long string
  • Under the magnet, lay out the iron  letters “Magnetism” just far enough away so the magnet can’t touch the letters
  • (The letters will need to be laid out in a circular arc, so the magnet can come close to each letter)
  • The magnet will initially hang vertically, attracted to the center letter
  • Allowing the public to pull the string will break the attraction, and set the magnet swinging, in chaotic/random patterns, until it eventually slows and stops over some letter.
  • By making the rope long enough (eg 3-4 meters) and the magnet massive enough (eg 1 kg), this would remain swinging in chatic motion for perhaps a minute before it finally came to rest. This provides something to look at for members of the public who are too shy to obey the sign and pull on the rope…
  • You could wrap one or two of the letters in a coil of wire, and provide external switches to turn each coil +/-/off, which will repel or attract the swinging magnet, giving it a magnetic “kick”. Two “players” could attempt to play football on this non-uniform magnetic field which induces a chaotic motion to the magnet. If they can get the magnet to swing beyond a line marked at the far end of the field, they score a goal…
  • The coils demonstrate “Electromagnetism”, where electric currents induce a motion at right-angles to the magnetic field (illustrated to physics students as the “right-handed rule” and “left-handed rule”). You could link to this concept artistically by  placing the letters “electro” at right angles to the center of the word “Magnetism”.
  • By placing coils of wire on the “electro” as well, you could have 4 or 8 switches at 4 sides of the display, allowing a 4-team football game on a magnetic field! 
 

The Naked Scientists Forum

Re: Need advice for a magnetic art installation
« Reply #4 on: 15/08/2013 23:17:16 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums