Hello, I am trying to calculate the capacitance of a MEMS based displacement sensor using the macro CMATRIX but I am facing some problems, I've tried different approaches but to no success. I shall mention here the specifications and the approaches with related error messages. Materials used in the displacement sensor: Si and air Element used for the Analysis: Solid226 (both Si an air) Analysis type: Static Solver: JCG Keyopt(4): 1 or 2 (both the cases) Youngs Modulus(Ex) of Si:169e3 in uMKVS 1)Approach one, with Youngs Modulus (Ex) of air as 1e-3 (As mentioned in the coupled field guide): With these specifications when i run the simulation i see a perfect displacement(Image:http://i.imgur.com/H6oZBTE.png),but the following errors and warnings appear. Error messages: Error message 1: "Element 2329 (type = 3, SOLID226) (and maybe other elements) has become highly distorted. Excessive distortion of elements is usually a symptom indicating the need for corrective action elsewhere. Try incrementing the load more slowly (increase the number of substeps or decrease the time step size). You may need to improve your mesh to obtain elements with better aspect ratios. Also consider the behavior of materials, contact pairs, and/or constraint equations. Please rule out other root causes of this failure before attempting rezoning or nonlinear adaptive solutions.If this message appears in the first iteration of first substep, be sure to perform element shape checking." Error messgae 2: "Load step 1 Substep 1 is not on file." Warning : "Coefficient ratio exceeds 1.0e8" In the above error element type 3 is air. As suggested in coupled field guide to morph air and to avoid air mesh distortion i removed the mid side nodes and increased the sub steps (nsubst,20,2002,20) as suggested in the error message,but to no success. Observation: The above errors and warning message does not appear in the solution process,but only when the CMATRIX macro is called. 2) Approach two, with Youngs modulus(Ex) of air as 1e3 with all the other previous specifications: No error message or warning appears and also the simulation results a capacitance value, but the displacement in the sensor is not as expected.(Image:http://i.imgur.com/yvrUVa2.png) I would be very grateful if Ansys guru's could point out any mistake I've committed and guide me in the right direction. Best regards, Mohammed Siraj Ghouri, (M.Sc)Micro and Nano Systems, TU Chemnitz, Germany.