DOC PREVIEW
Berkeley ELENG C247B - Problem Set

This preview shows page 1 out of 2 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 2 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 2 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

EE C245 / ME C218 INTRODUCTION TO MEMS DESIGN FALL 2009 - 1 - PROBLEM SET #5 Issued: Thursday, Oct. 22, 2009 Due (at 7 p.m.): Thursday, Oct. 29, 2009, in the EE C245 HW box in 240 Cory. 1. The figure below presents the top view of a small micromechanical filter constructed in a 2μm-thick structural layer. Here, everything is suspended 2 μm above the substrate except for the anchoring locations indicated as the darkly shaded regions. Data on the structural material used in this problem is given in the box below the figure. Also, assume that all folding trusses and shuttles are rigid in all directions, including the vertical (i.e., z) direction. Also, assume that all suspension and coupling beam widths are 2 μm. (a) Write an expression for the static spring constant in the x-direction at location A in the figure and calculate its numerical value (with units). (b) Write an expression for the static spring constant in the x-direction at location B in the figure and calculate its numerical value (with units). Structural Material Properties: Young’s Modulus, E = 150 GPa; Density, ρ = 2,300 kg/m3; Poisson ratio, ν = 0.226 DI Water Contact Angle for Structural and Substrate Materials: 85o Water-Air Interface Surface Tension: 72.75×10-3 N/m Input ElectrodeOutput ElectrodeCoupling BeamAnchorsAnchorsSuspension BeamShuttleFolding TrussA100 μm200 μm2 μmB60μm×5μm40μm×5μmEE C245 / ME C218 INTRODUCTION TO MEMS DESIGN FALL 2009 - 2 - (c) Suppose an incomplete HF/DI rinse release step were performed, after which the shuttles were not fully released, but all suspension beams and folding trusses were successfully released. Using the data in the figure, will the coupling beam folding trusses be stuck down? 2. A simple beam of length L is subjected to a concentrated load P at location c while being compressed by two equal and opposite forces S as shown in the figure. (a) Derive an expression for the deflection w as a function of location x, i.e., get w(x). (b) Determine the deflection and the spring constant at c=L/4 and c=L/2, respectively. 3. Suppose a cantilever beam of length L is subjected to a uniform load of intensity q and a concentrated load P at the free end of the beam. (a) Derive an expression for the deflection w as a function of location x, i.e., get w(x), using the principle of virtual work. (b) Determine the deflection at the free end and the spring constant if q=P/L. PcL-c-S -S xP


View Full Document

Berkeley ELENG C247B - Problem Set

Download Problem Set
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Problem Set and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Problem Set 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?