The Black Art of Casting Silver Heating Elements

 

Those of you familiar with our heating and freezing stages know that we use a silver heating element. You may also know that the element is cast using the lost wax principle which has been used to make jewellery and bronze statues for thousands of years and the process remains in principle relatively similar today.
However, when casting a bronze statue or a bit of jewellery, it is only the surface finish that we are interested in.  When it comes to casting a silver heating element used in our Linkam stages, you not only need a perfect finish on the top surface where the sample sits but there cannot be any voids in the structure (except the channel for liquid nitrogen.) as this will effect the high resolution temperature control.
This important fact is what has kept us awake at nights trying to formulate the perfect conditions to create the perfect consistent cast.  There are so many parameters that need to be perfectly controlled that it is nothing short of a miracle that we turn out as many perfect blocks as we do.  Even then, there are many more steps to complete the heating element where things can go wrong, I can't believe that our assembly engineers haven't gone totally crazy with frustration.  (See image above: The reject box)
We are always trying new ways to improve the process.  Over the last 30 years our engineers have pretty much read everything there is to know about casting and talked to dozens of experts in the field.  Nobody has managed to cast our heating elements as well or as consistently as we can do it here at the factory.  In fact two of our engineers are currently in Germany talking with one of the leading casting machine manufacturers to discuss our casting protocol and see if they can help. 
So next time you take a look at that little gleaming heating element in your hotstage, have a think about the amount of work that went into it and perhaps spare a moment to consider that in the thousands of years that people have been casting, we may just be the best at it.