MICRO-ELECTROMECHANICAL NOZZLE ARRANGEMENT HAVING CANTILEVERED ACTUATOR
A micro-electromechanical nozzle arrangement for an inkjet printhead includes a substrate defining an inverted pyramidal ink chamber with a vertex thereof terminating at an ink supply channel defined by the substrate, said substrate having a layer of CMOS drive circuitry; a roof structure connected to the drive circuitry layer and covering the ink chamber, the roof structure defining a fluid ejection nozzle rim above said chamber; a plurality of actuators fast with and displaceable with respect to the roof structure, the actuators radially spaced about the nozzle rim between the guide rails, each actuator having a serpentine heater element configured to expand thermally upon receiving current from the drive circuitry thereby moving said actuators into the chamber and increasing a fluid pressure inside the chamber to eject a drop of ink via the ejection nozzle, wherein each actuator is cantilevered to a heater element in a bendable manner; and a central arm which having metal and PTFE portions to provide structural support for the actuators.
1 . A micro-electromechanical nozzle arrangement for an inkjet printhead, said arrangement comprising:
a substrate defining an inverted pyramidal ink chamber with a vertex thereof terminating at an ink supply channel defined by the substrate, said substrate having a layer of CMOS drive circuitry;
a roof structure connected to the drive circuitry layer and covering the ink chamber, the roof structure defining a fluid ejection nozzle rim above said chamber;
a plurality of actuators fast with and displaceable with respect to the roof structure, the actuators radially spaced about the nozzle rim between the guide rails, each actuator having a serpentine heater element configured to expand thermally upon receiving current from the drive circuitry thereby moving said actuators into the chamber and increasing a fluid pressure inside the chamber to eject a drop of ink via the ejection nozzle, wherein each actuator is cantilevered to a heater element in a bendable manner; and
a central arm which having metal and PTFE portions to provide structural support for the actuators.
2 . The nozzle arrangement of claim 1 , further comprising a series of struts interspersed between the actuators to support the nozzle rim.
3 . The nozzle arrangement of claim 1 , wherein the serpentine heater element is made from gold.
4 . The nozzle arrangement of claim 1 , wherein the roof structure includes ink flow guide rails to minimize wicking along the nozzle rim according to surface tension effects of ink in the chamber.
5 . The nozzle arrangement of claim 1 , wherein the actuators include a polytetrafluoroethylene (PTFE) layer.
6 . The nozzle arrangement of claim 1 , wherein the ink supply channel is created by means of a deep silicon back etch of the substrate utilizing a plasma etcher.