Thermally actuated vents for electronic devices. The method includes processing a semiconductor substrate of known impurity levels in an epitaxial reactor, and measuring the impurity levels after epitaxial processing by drawing together at least a portion of the impurities and measuring the concentration of impurities that were drawn together. The suspension comprises a piezoelectric element attached to the first pad and extending across the second pad. The metallic films provided in the present invention can be used for contact metallization, metal gates or as a diffusion barrier. The non-extrusion ring is comprised of hard segments and an elastic matrix. The configuration above offers stable sinusoidal-wave drive, reducing vibration noise of the rotation drum, the compressor and the blow fan.