A micromechanical actuator having the ability to move in two directions. The actuator can be manufactured in planar arrays using semiconductor manufacturing equipment. The planar array of actuators can be used as a microcillia array. The actuators are formed from two layers of electrically resistive material which are used to heat a non-conductive material which has a high coefficient of thermal expansion. The pattern of resistive material in the two layers is arranged such that the actuator can be bent in two directions, both in the plane of the actuator and normal to the plane of the actuator.
A method of calibrating a micro electromechanical device in the form of an ink ejection nozzle having an actuating arm that is caused to move an ink displacing paddle when heat inducing electric current is passed through the actuating arm and having also a movement sensor associated with the actuating arm. The method comprises the steps of passing a series of current pulses of successively increasing duration t.sub.p through the actuating arm over a time period t, detecting for a predetermined level of movement of the actuating arm within a predetermined time window t.sub.w, and calibrating the device for subsequent actuation by a current pulse having a duration t.sub.p sufficient to produce the predetermined level of movement within the predetermined time window t.sub.w.
A micro electro-mechanical device embodied within an ink ejection nozzle having an actuating arm that is caused to move an ink displacing paddle when heat inducing electric current is passed through the actuating arm. The device incorporates a movement sensor that comprises a moving contact element that is formed integrally with the actuating arm, a fixed contact element that is formed integrally with a support structure of the device and electrical elements formed within the support structure for detecting contact that is made between the fixed contact element and the moving contact element. The movement sensor is provided for the purpose of facilitating testing of the device under various operating conditions.
Linear bimorph actuators are cascaded together in serpentine array structures to achieve large angle rotary displacements. Bimorph units contain single material beams that remain straight when heated coupled with substantially parallel bilayer beams that deflect when heated, due to differential thermal expansion of the layers. For a bilayer beam, advantageous materials are gold on top of polysilicon. The angular deflection is amplified by cascading to achieve cumulative rotational displacements up to greater than 90 degrees. Successive beams can be connected electrically in series to provide a continuous current path for resistive joule heating. In various embodiments, the actuator is fully permanently anchored or releasably attached to a substrate, or at least a segment of the substrate is removed from beneath the actuator to prevent mechanical interference. Embodiments enable single and plural-axis rotational displacement and manipulation of payloads, for example microcomponents, mirrors, and pick-and-place devices.
An inkjet printhead is formed on a substrate incorporating drive circuitry for the nozzles of the printhead formed by a CMOS process. One or more of the layers formed by the CMOS process are utilized as a sacrificial material layer in forming the actuators or paddles of the ink ejection nozzles formed by MEMS process.
A method of testing a micro electro-mechanical device in the form of an ink ejection nozzle having an actuating arm that is caused to move an ink displacing paddle when heat inducing electric current is passed through the actuating arm and having also a movement sensor associated with actuating arm. The method comprises the steps of passing a current pulse having a predetermined duration or a series of current pulses having successively increasing durations through the actuating arm, and detecting for a predetermined level of movement of the actuating arm.
