Thermal inkjet with multiple drop volumes per nozzle

A pagewidth printhead comprising:

• a printhead controller;
• a wafer substrate that defines a plurality of inlets;
• and
• a plurality of micro-electromechanical nozzle arrangements on the wafer substrate and under control of the controller, each nozzle arrangement comprising:
• side walls located on the wafer substrate with a roof portion attached to said walls to define a printing fluid chamber in fluid communication with one inlet, the roof portion defining an ejection port;
• and
• a plurality of heater elements suspended between the side walls in the fluid chamber, so that when electrical actuation energy is applied to respective heater elements a vapour bubble is formed in the fluid leading to a pressure increase in the chamber thereby ejecting the fluid via the ejection port, wherein
• the controller is configured to actuate respective heater elements individually to facilitate ejection of weighted ink drop volumes from the nozzle arrangement, and
• a mass of the heater element is less than 2 nanograms.