Abstract: A method of making an actuator for a resonant acoustic pump comprises: forming a through-hole in a ceramic material of a piezoelectric layer of the actuator, prior to assembly of the piezoelectric layer with other layers of the actuator; forming a through-hole in a flexible circuit layer of the actuator; forming a through-hole in an end plate layer of the actuator; and disposing each of the piezoelectric layer and the end plate layer on a respective one of opposite sides of the flexible circuit layer, so that the through-holes align to provide a passageway for a fluid to pass through the actuator.

Abstract: A control unit includes a rotatable tubular body that rotates around a spindle. A torque transfer unit may be attached to the tubular body and the spindle. A force applied to the torque transfer unit by a biasing element may control a first torque applied by the tubular body to the spindle. The first torque is independent of a rotational velocity of the tubular body. A second torque is applied to the spindle with a torque generator, the second torque controlling the net torque. Controlling the net torque allows the absolute orientation of the control unit to be controlled.

Abstract: A control unit includes a rotatable tubular body that rotates around a spindle. A torque transfer unit may be attached to the tubular body and the spindle. A force applied to the torque transfer unit by a biasing element may control a first torque applied by the tubular body to the spindle. The first torque is independent of a rotational velocity of the tubular body. A second torque is applied to the spindle with a torque generator, the second torque controlling the net torque. Controlling the net torque allows the absolute orientation of the control unit to be controlled.