Abstract: A material ejection system, a print head, a 3D printer, and a method for material ejection is provided. The material ejection system comprises: a housing; a plate provided in the housing and dividing the housing in an upper space and a lower space, wherein the lower space is configured to hold a material for ejection; a controller unit; one or more material ejection units each comprising: a membrane formed by two essentially parallel slits in the plate, a first electrode provided above the membrane in the upper space, a piezoelectric element provided on the first electrode, a second electrode provided on the piezoelectric element, wherein the first and second electrodes are each electrically connected to the controller unit for providing a voltage to the piezoelectric element, and an extension member provided underneath the membrane extending into the lower space.