Once we determined that we wanted the magnetic particles to grow vertically, we started to construct the mechanism to move the magnets upwards. After some early experiments with a servo, we realized to attain the range of motion that we wanted from the magnets we needed to use a DC motor to turn a lead screw. The magnets were attached to a nut that would turn up and down on the lead screw. The prototyping of this mechanism ended up being more challenging than we anticipated. This was partially because of the fact that the motor and lead screw connection had a tendency to break with the glue cement we had used initially, as well as the fact that the magnets would be attracted to the DC motor (which we had to dampen with several pieces of felt).