The VP 581B-MICA is almost identical to the VP 581A-MICA except in the thickness. The VP 581B-MICA is 6 mm shorter than the VP 581A-MICA. This facilitates applications where the Z height is limited. Also the shorter height translates to a lower price.
The VP 581B-MICA was designed to attach to the bottom of our heat blocks and locate the heat block in a microplate holder on a robotic deck. The heat blocks are attached to the VP 581B-MICA so that the microplates they hold, will be in the same relative position as if they placed in the holder on a robotic deck. Thus the robot will not have to be reprogrammed to find the correct X and Y positions.
The VP 581B-MICA is made from Muscovite, a very high temperature stable Mica which is dimensionally stable over a temperature range of -80C to 500C. This is a very important characteristic as high temperatures can induce swelling of polypropylene and PTFE material to the point where they won't fit in the microplate holders on the robot deck. This heat induced swelling of material is a problem for our polypropylene and PTFE versions of the VP 581B and the reason we developed the VP 581B-MICA. We recommend this product over the other materials we have used for heat blocks in the past.
The Muscovite Mica is also a good insulator and a way to prevent or reduce heat from the heat block transferring to the robot deck. The Muscovite Mica is safety rated by UL laboratories as UL 94VO.