sensoaesthetics

Imagine a solid that was a better insulator than almost any other solid and that, at the same time had a very low density - getting down to the density of air at sea level.  I was paging through some papers in the latest issue of Nuclear Instruments and Methods and had just run into aerogels for the first time.¹  They seemed amazing and I had to see some for myself.  Unfortunately they were very exotic at the time and that meant I had to figure out how to make a sample.  Fortunately there was serious interest in experimental particle physics community and our group had access to the instrumentation section of Brookhaven National Laboratories - sort of a playground for building exotic detectors and electronics.

 

It took some calls and emails (yes we had email in the late 70s) to groups in Switzerland and Japan, but we managed to get enough of the basic tricks to give it a try.  We ended up writing a few papers on its properties - the fact that its index of refraction was a bit higher than gases, but much lower than liquids and solids made it an interesting candidate for Cherenkov detectors - and, if you could figure out how to lower the cost and increase its stability, it would make a dandy insulation material for homes, refrigerators, electric cars and a thousand other applications.  People are still playing.  It is one of those amazing materials with a few applications that may - or may not - have a serious impact on more common technologies.

 

Playing with materials is something that is expected in physics as much of the apparatus you need to build for an experiment is unique.  I grew up learning how to work with wood and do simple metal work - soldering, bending and a bit of welding.  When I entered grad school it was clear this wasn't enough, so I took a metal working class and learned the basics of how to use milling machines, lathes and a few other tools I never had access to.  Once I demonstrated competency by building a couple of screw clamps (the department was clever - there was always a need for clamps, so the shop qualifier was to build some and donate them to the department) it was time for a more sophisticated project to start to develop my skills.   I went to the library and located a copy of an ancient Popular Science magazine I had first read when I was about 12 or 13.  It had a construction article for a Stirling engine.

 

For some reason the project captivated me as a kid.  I had been trying to sort out how various heat engines worked and the old Stirlings were very unusual and attractive.  I thought it would be neat to use concentrated sunlight from a large mirror as a power source.  The problem for a kid was not having the tools or skills - thinking and dreaming only goes so far..  Now I had a shot at it.

 

Magazines like Popular Science were full of projects aimed at hobbyists of varying skill levels.  Most involved wood working, but every issue had a metal project or two and some were very sophisticated - a retired craftsman showing off his prowess by building a diesel engine smaller than the tip of your thumb or a one eighth scale twelve cylinder Ferrari engine that ran.  The more interesting projects that a competent hobbyist might have a shot at had blueprints you could send away for.  Unfortunately the blueprint service was long out of business by the time I got around to the project - heavens, the issue was much older than I was.  So I drafted my own design based on the article along with a few books on Stirling engines from the Stony Brook engineering library and figured out what types of aluminum, steel and brass I would need.  The only store-bought bits were the SKF ball bearings.  

 

It took a few days of spare time and worked right off the bat.  I got about 30 watts at 1,500 rpm from it.  Not very impressive, but I was happy.  I never got around to the mirror - I used a blow torch as a heat source making this one of the more inefficient engines around.  

 

But it was fun and that was the point.  I like to build things now and again.  A few people confuse that with engineering, but I'm not an engineer.  They would approach the design problem from a different angle and I'm sure it would work better.  None of my projects, apart from experimental apparatus, are serious - it is only fun.  An artifact of the era I'm from.

 

Before the 1970s making or repairing the things in your house was common - a hobby for some, a money-saving necessity for almost everyone.  Most the families I knew had a sewing machine and a wood shop. A few went beyond that basic level.  It wasn't unusual for a teenage girl to make or modify clothing or a boy to tinker with a junker car to learn about the mechanicals.  For many building things was more interesting than television, which was fairly limited in our area, and many people had the basic skills.  Shop and home economics courses in the schools were mandatory - the ability to make as some level was part of education.²

 

Building skills are rarely taught in schools these days.  All of the shops closed long ago in our district.  The same is true for sewing and cooking.  People tend to buy finished goods these days - often poorly made and unrepairable, but very inexpensive.  We buy and discard.  It has been a delight to see the pendulum start to swing back towards the makers.  Magazines like Make and a variety of websites (Adafruit is neat as it is aimed at women) are teaching people how to build projects, sophisticated electronics are making it possible to build relevant kit that appeals these days and new classes of tools; 3D printers, laser cutters and a variety of CNC machines are available.  A few locations - Seattle, Portland, Brooklyn, Minneapolis, San Francisco, and Cambridge come to mind - have sprouted maker spaces ..  locations where people share the cost of a set of tools and build in an environment with a lot of hands-on instruction.  

 

All of this is wonderful, but it isn't happening as rapidly as many would like.  In particular there is a lot of hand-wringing about the slower-than-expected adoption of 3D printing.  Some suggest that the sewing machine should be a model - after all, it was the  first complex standardized technology that was mass marketed. I don't think that gets at the heart of the problem.  The big issue is what Horace would point out - 'what is the job to be done?'  Many advocates see a future where the 3D printer is an appliance that simply builds what you need - saving the need to have a factor fabricate something that would need to be shipped.  At this point that is a very naïve view and you have to worry about the materials problem and the jobs that are accessible in the nearer future.  There are a several issues that need to be tackled.

 

I'm nearing the end of my hour .. I'll continue this in the next day or two writing about why the sewing machine was successful - three separate elements had to come together at the right time after about six decades of not quite good-enough invention and improper timing relative to another set of technologies.  

 

But until then the thought I want to leave on is embodied in the strange title of the post.  Materials are widely varied and incredibly important.  The number of materials that can be used in 3D printers is a very limited at this point.  People who get into making things find these tools just that - tools.  Extremely useful for prototyping and a few parts that aren't terribly constrained by material choice.  Printing is still  expensive relative to most forms of production, but the technique can be used to enhance certain types of production.  If you had enough money to build a proper shop you would buy a 3D printer, but the laser cutter and CNC milling machine are probably going to be much more useful.³ 

 

Going beyond fabrication is design and materials choice.  Most people aren't designers and have to use the work of others, perhaps making small changes.  But for those who design there must be design skills and tools.  I had enough to design a Stirling engine with pencil, paper, straight edge, compass and my old HP35 calculator.  The tools required for 3D printers have a much steeper learning curve and few have the basic design sense to produce useful items even if they can use something like AutoCAD.⁴

 

But a fundamental component is the choice of material. Something that Apple usually nails and something we admire in other products we associate with good design.  The right metal with the right distribution of weight, a type of wood with a grain that you just like to look at and a smooth beveling of the edges that invites touch.  Even the smell of something or the sound of its operation ...  sensoaesthetic design is subtle, but extremely important.  It can elevate a set of components from mainstream to luxury and, if inexpensive enough, can cause issues for competitors.  

 

... to be continued 

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¹ For a grad student in experimental physics some of the articles were science porn.

² They were also sexist. During my junior year one of the girls managed to argue her way into metal shop so she could learn how to weld.

³ A strong recommendation - if you have the slightest interest in how things are made Making It, Manufacturing Technologies for Product Design 2^nd Edition by Chris Lefteri is a wonderful little book.  Very high level, but fascinating,  Mine is completely filled with annotations and is heavily dog eared after just a year.

 ⁴ If you really want to learn about 3D printers, spend time learning how to use the design programs.  You can send the files to quickturn fabrication companies that will give you much better results than any machine you can afford to buy and maintain.  3D printing, for the amateur, is probably best left to a remote service at this point.

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Recipe Corner

 

Just a quick suggestion. Avocados have been good and inexpensive.  One of the best sandwiches I've had in a long time had a filling of one mashed with finely chopped onion, tomato, pickled peperoncini, dried cranberries, pecans and a squirt of lemon or lime juice to slow oxidation of the avocado.  A bit of sea salt (watch the amount as peperocnini is often salty) and freshly ground pepper and between two sheets of toasted rugbrød.  (I'm a big fan of very dense breads ..  the rugbrød is necessarily homemade, but a good enough substitute is a dense commercial German bread like Mestemacher rye or three grain.)