How To Tear/Rip Apart Your Smart Mass Putty

    Lots of people will try to separate putty into two pieces by stretching and stretching. This takes forever and creates a long strand of thin putty. Hold the putty as seen in the photograph. Dig the nails of your thumbs and forefingers into the putty.

    The tear is going to be made only one finger. In this example we are going to tear towards us, using our left hand. If you are right handed then you can reverse the motion. With a quick and sure motion use your left forefinger to rip the putty towards you and to the left. Just rip it!

    On the first couple of tries, you may end up just stretching the putty. Try to move quicker with more force. You'll get it eventually. Normally when you stretch the Thinking Putty, the molecules realign themselves with the direction of motion. Herding together like sheep they stay attached to each other and let you stretch. By moving quickly you don't give the molecules inside the putty time to realign themselves with the direction of motion. Instead of flowing they tear apart.



      If You Really Want To, You Can Shatter Your Smart Mass Putty !!

      The Scenario:
      What happens when you hit Smart Mass Putty with a hammer? IT SHATTERS! Doesn't seem to make any sense does it? You play with Smart Mass Putty BECAUSE it stretches and melts and acts like a real liquid solid. So what's the skinny?

      The simple answer:
      Smart Mass Putty displays four different properties on four different time scales. At very long timescales, it behaves like a liquid spreading out onto a flat surface. At moderate timescales, the Smart Mass Putty stretches like a plastic solid. At short timescales, it bounces like an elastic solid. And, at very short timescales (the impact of a high-speed projectile), the Smart Mass Putty simply shatters.

      Smart Mass Putty is a dilatant compound, which means it becomes solid under the influence of pressure. If you've ever played with Oobleck, you've experienced the same properties.

      The complicated answer for all you Chemistry Majors:
      Some of the behaviors listed above are an example of a dilatant compound, where the viscosity (i.e. the resistance to flow) increases faster than the strain rate. Although not common, some materials do exhibit dilatant behavior (concentrated aqueous corn starch suspensions -- read: Oobleck).

      However on its own, this is not enough to explain the behavior of Smart Mass Putty. In fact there are two mechanisms (and hence two characteristic time scales) at work.

      The high molecular weight of the primary ingredient PDMS (Poly Dimethyl Siloxane) has a characteristic polymeric relaxation time, defined by the time that a random walk allows the chain to relax from a stretched state through thermal vibrations.

      However due to the Boric acid (the fourth ingredient by weight), there are also transient Boron mediated crosslinks (and you thought I was kidding about the chemistry major bit) arising from associating Boron linkages. These act to give the Smart Mass Putty a behavior more like an elastic solid than a liquid.

      However since these crosslinks are dynamic, the material is not permanently locked in place and can consequently flow under the correct conditions. Therefore at longer time scales, the Smart Mass Putty behaves like a high molecular weight polymeric fluid. (Still here? Wow, you must be really interested!)

      Over very short time scales the putty behaves like a crosslinked elastic solid, shattering like a ceramic on impact. QED.



        Smart Mass Putty Can Drip From The Ceiling!!

        This is a great trick that always elicits a great response. The first step it to take a big handful of Thinking Putty and make a symmetrical cylinder (pictured is two tins of our Atomic Bronze putty - but one works just as well). Next, with your finger create a slight indentation three quarters of the way to the bottom of the cylinder. Stand on a chair (Should we warn you about the danger of standing on a chair while trying to reach the ceiling by standing on your tippy-toes?) and firmly stick the Smart Mass Putty to the ceiling. Make sure the indentation is facing the ground.

        Now watch and wait. Slowly the putty below the indentation will make its way to the table/floor/etc. If you've gotten your indentation right, you can watch a thin strand of Thinking Putty pouring from the ceiling. It's like watching molasses run, only cooler! It's hypnotic and can last a really long time with a little luck and a little practice.