Dawn in Antarctica

I made quite a few modifications to the tripod for Ian.  The most important change was taking apart the micromanipulator to reduce its mass.  I kept only two adjustments: a coarse adjustment and a fine adjustment, both parallel to the axis of the micromanipulator. Then I bought some nice Ikelite ball joints that are designed for underwater lighting systems.  I mounted one of them on the slider that moves up and down one of the tripod legs and one on the mini-micromanipulator.  They can be clamped directly to each other or a 6 inch bar can be clamped between them. The manipulator is significantly less stable with the 6 inch bar, but it can reach almost anywhere within the tripod.  Without the bar, the microelectrodes can still reach a wide range of angles and mats.  In addition, I added disks (plastic electrical covers) for feet to help the tripod settle nicely on the mat. If we want spikes as well, I can put long screws through them.  It...

My colleague and friend, Ian Hawes, can spend half an hour diving in 0.5°C water patiently moving a mini-electrode into a microbial mat with a micromanipulator.  (He prefers 3°C water or maybe even 20°C water.)  However, there are times when his patience is pushed beyond the limits, for example when the geometry of the micromanipulator (attached to a stake pounded into the lake floor) doesn't let him position the electrode properly. After the last field season in Antarctica, when he couldn't measure O 2 gradients in the vertically-oriented microbial webs we found, we talked about designing a tripod that would give him more flexibility with the micromanipulator geometry.  I've been working on that tripod. The idea is to have a light-weight tripod that can be placed over an area of interest and to be able to move the (attached) manipulator to measure the O 2 concentrations and pH in mat oriented from horizontal to vertical.  I'm part way there with my design, parti...