12 July 2011

tiny profiles

11.7.11
(i do like a palindromic date) 
Back in the lab. Briefly. I bumped into L in the corridor, and asked if she was going to be in the cleanroom, which she was, and so asked if I could accompany her, which I could. So I did. Her task of the moment was to measure the thickness of a film on a substrate. She hence coated said substrate, which looks extremely like a piece of glass (about 1.5 cm square) by adding her solution (a clear one, a couple of drops) and spinning it for 30s in a centrifuge-type machine. All of this took place in one of the clean boxes with her manipulating the sample and equipment via the arm-long black rubber gloves (they are the arm equivalent of thigh-high boots, but I cannot think what the word to describe them in that way would be. Were they boots they would be very kinky – stretchy, close fitting, limb-long rubber - but as gloves they are somehow so very prosaic. Nonetheless I cannot resist the temptation to see how it feels.). I put my arm into one of the gloves, fingers into inverted fingers then rolling into it from there up – already ensconced in two pairs of shoe covers, a full length Tyvek suit, two hoods, gloves and spectacles I felt somewhat encumbered. Goodness only knows how they conduct any subtle actions buried under so many layers. Prior to working on her sample L had to get it into the clean box, which requires it going in through a little evacuated ante-chamber. This chamber was flushed three times with nitrogen gas (that’s what is in the clean box), and then the sample moved into the chamber. She explained her process as she went along, and I struggled to hear amidst the rustlings of many layers of clothing and background machine noise. L is working with Ravi Silva, who is the director of the ATI, and who works (in part) on solar cells, his group exploring new materials and methods to make them more efficient, longer lived, smaller, etc. After the transparent fragment is coated with the transparent coating L removes the sample from the clean box and scratches the surface, in order to be able to measure the profile across it. This is undertaken using a profilometer. A profilometer is basically a probe that is dragged across the surface of something and which records the topography of the surface. I love that kind of technology; I imagine it to have been around for hundreds, maybe thousands, of years in almost the same form. The form of this one is somewhat twentieth century, being a rather fetching brown and beige computer-looking machine. On the label it says 1994, but to me it is reminiscent of a computer my dad bought in the early 1980s, all ergonomic curves and a small, embedded, flickery screen. Apparently it is so knackered that they can’t switch it off, and must simply turn the brightness and contrast down. L measures the profile and I get caught up in drawing the machine – as ever in the cleanroom I am restricted to using the shed-free paper and biros and pens. In the university shop on the way in to the lab I had stumbled upon a cherryade-scented pen, and so my drawing becomes a multi-sensual event. The profiling completed L must go to have a meeting with Ravi. We leave the clean room, disrobing in the ante-chamber as we flush back into the audible, unclean world.

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