A micro-mirror strip assembly having a plurality of two-dimensional micro-mirror structures with improved deflection and other characteristics is presented. In the micro-mirror structures, electrodes for electrostatic deflection are disposed on conical or quasi-conical entities that are machined, attached or molded into a substrate. Torsion sensors (244) are provided along the axes of rotation to control deflection of the quadrant deflection electrodes. The shielded sensor structure (240) includes a silicon layer (241), an insulating layer (242) and a metal layer (243). The structure further includes a sensor implant resistor (244) in the silicon layer (241) and a shield (245) that is applied over the sensor implant resistor (244) to stabilise sensor output and eliminate light sensitivity.