Low physical restriction MEMS potentiometer using probe dipping μpool with conductive liquid

This paper presents a MEMS potentiometer that uses a connection through a probe dipping into a μpool (hereafter PDP-connection). We proposed a PDP-connection to minimize physical restrictions that cause serious problems for microactuation. A PDP-connection employs a probe electrode that is dipped into a μpool filled with a conductive, nonvolatile liquid. A PDP-connection works as a variable resistor for a potentiometer as well as low restriction wiring. The proposed potentiometer can drastically reduce the physical restrictions at the contact point of a variable resistor. This permits the position of a movable object to be detected without restricting its motion. The developed potentiometer based on the PDP-connection using Φ 20 μm probe could detect displacements of 2 μm with good linearity. The measured restriction force was a few mN at 5 μm/s motion velocity, whereas a commercial potentiometer requires at least 100 mN.