haha. Those batteries are actually all dead, as I was planning on walking them down to the battery recycling box in the hospital, but I was looking around for some non-stick round things that wouldn’t float…
Does it cure that color/consistency? 
You can always use failed batches in some diapers and sell as novelty/gag gifts ! 
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Is “dead” for your batteries actually dead, or just under 0.8V?
Either the pager has the open battery symbol and starts beeping (and before someone raises it, yes we still use pagers, yes that seems archaic but it does things you can’t easily do with a smartphone - including survive radiation exposure, work in the boiler rooms 2 stories underground with shielded walls, etc - and yes we are high tech and know what we are talking about) or the mouse was blinking where it was insufficient to maintain mouseness (using @Dan’s terminology). So they are likely functionally dead, and not electrically dead…
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OK, so mid-day awesomeness report. For those of you occasional silicone users, did you know you can pour and cure silicone on top of water? So this morning, had 10 minutes to get this ready, keeping the block in the mold, pulled the batteries out. Poured DragonSkin 10VF silicone in a thin layer of the holes made by the batteries, immediately filled the holes up with water used a paper towel to get the meniscus below the top layer, then poured the remainder of the silicone on top of the water. 10 minutes later:
Then off to the interventional radiology suite for testing:
For comparison my bicep (the round hole is my cephalic vein); note all the “stuff” (yes, that is the term we learned in anatomy) in the arm. The next issue is getting stuff into our silicone.
How many interventional radiologists does it take to stick a needle in a phantom?
Here is what it looks like on the outside
Here is the view via ultrasound with the needle advanced into the lumen of the Duracell-Artery
Now it turns out that my silicone is too “clean” and there isn’t enough speckle. So I am adding a layer of crap on top (DragonSkin 10VF with a bunch of different powders in it to see if that makes it more like my arm).
What’s cool is the commercial phantoms we buy which look sort of like my block are around $500, and we expect to make these in the <$15 range internally…
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can you apply a vacuum to it? that might get the bubble out. coupled with some vibration?
In other silicones probably not an issue, but the “VF” stands for VERY FAST (all caps deliberate) because it cures insanely fast. As in be reeeeeeaaaaaally ready to go once you mix. It is completely hard in 10 minutes. Mis-En-Place is your total friend. Just doing the paper towel was stressful.
This is also just a throw away test today to try and match the densities. For real, the water is in a closed-loop pump system so the blood is flowing (actually pulsing since I use an Adafruit feather controlled peristaltic pump to produce pulsatile flow)
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I wanna work where you work this is all so cool
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That is a fast setup time. Whew!
So this part of my job is the fun awesome part where I get to create and solve problems, the rest of the time not so much…
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That would be why it is still called a job. You are obviously very well suited to the work you do!
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Exactly what I was thinking!! What a gross color!
Have you ever tried Dragon Skin FX Pro? It’s my go to for creating any kind of “skin”.
I normallly use dragon skin 10 extra fast