Clamped square membrane

An example of a clamped square membrane with a piezoresistor around the edge to detect the strain from the membrane deflection is shown in Figure 2.19. The membrane and piezoresistor have been meshed for finite element analysis. 

Figure 2.19 Clamped square membrane with a pressure P applied to the back face. (Left) Undeflected membrane. (Right) Deflected membrane with color keyed to displacement. (Reprinted with permission of Sandeep Akkaraju from IntelliSuite v8.6 (2010), IntelliSense Software Corporation.) See color plate section.

Thermomechanical Valves, Fig. 1 (a) Schematic diagram of a straight, clamped-clamped beam after buckling (b) illustration of the thermal buckling of a square membrane... 

Figure 2.13 Deflection of released membranes. (Left) Clamped circular diaphragm with thickness t and radius r subjected to a point load P at its center. (Middle) Clamped circular diaphragm subjected to a distributed load q N/m or Pa. (Right) Clamped square diaphragm with sides of length a subjected to a point load P at its center. (Reprinted with permission from Prof. Hiroshi Toshiyoshi, Institute of Industrial Science (IIS), The University of Tokyo, Japan.)...

Permeability Studies. A two-chamber diffusion cell procedure (8. 12) was employed with freshly excised hairless mouse skin. The diffusion cell consisted of two half cells or compartments (2 ml volume/half cell) and the area for diffusion between the two half cells was approximately 0.6 cm2. The full-thickness skin membrane was prepared by sacrificing the mouse as previously described and excising two square sections of the left and right abdominal skin. A skin membrane was mounted between the two compartments of the diffusion cell with the dermis side facing the receiver compartment, clamped and excess skin trimmed. The assembled diffusion cells were immersed in a water bath at the selected temperature between 10 and 60°C. Glycerine baths were used for temperatures between 60 and 90°C. Each compartment was filled with PBS adjusted to 7.3 pH at the specific experimental temperatures. 

Mechanical evaluation of the tensile properties was performed on a Tinius Olsen HI OKS bench top tensile tester at a speed of 5 mm min". A stretching force was applied to one pneumatic clamp. Clamp displacement was used to determine elongation ratio and strain. Tensile stresses were calculated from the initial cross-sectional area of the sample and applied load. Young s modulus, E, were determined from the initial slope at A = 1.025 (least squares fit, s = 2.5%). Three to five samples per mechanical measurement were used, with estimated error/uncertainty not exceeding 10% in the data. The membrane samples were cut into a rectangle shape 50 mm X 4 mm (total) and 25 mm x 4 mm (test area). 

Pre-wet a 90x130 mm nitrocellulose membrane in PBS for 30 s. Place the membrane squarely onto sheets of blotting paper cut to the same size pre-wetted with PBS. Clamp the nitrocellulose and blotting paper assembly between the upper... 

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