An active spindle system with an Electro-Magnetic Actuator (EMA) is developed for micromachining. The process of developing controllers for this mechatronic system requires reasonable models that expose the important dynamic effects without being excessively complicated. This paper develops a MIMO model with four inputs and two outputs based on the bond graph method. This model considers the bidirectional bearing compliance as well as the external load effect. System state space equations are produced automatically from the bond graph model. Simulations in several conditions are done in both time and frequency domain. Results from simulation and experiments are compared.
We propose a micromachined 2x2 optical switch with variable optical attenuation. The proposed optical switch features expandability and integration utilizing four 45° micromirrors driven by four electrostatic comb actuators. These four micromirrors can move independently to reflect and/or partially block the optical signal. In order to reduce the insertion loss caused by long optical path length, the optical module employed anti-reflection coated lensed fibers. Two pairs of optical fibers were aligned in each single trench at both sides for cost-effective packaging. The device was fabricated using SOI (Silicon-On-Insulator) process with one photo-mask, and its experimental IL (Insertion Loss) and attenuation range were less than 1.53 dB and over 60 dB, respectively. Also the PDL (Polarization Dependent Loss) was less than 0.25 dB in the range of 30 dB.