Abstract: Micromachining, etching and bonding techniques are employed to fabricate hermetically sealed gas-filled chambers from silicon and/or glass wafers. The hermetically sealed gas-filled chambers have precise dimensions and are filled with a preselected concentration of gas, thus rendering exceptional performance for use as an optical gas filter. The first step involves etching one or more cavities or holes in one or more glass or silicon wafers. These wafers eventually become part of a chip assembly having one or more hermetically sealed gas-filled chambers after appropriate bonding procedures. Interfaces between aligned silicon wafers are bonded using fusion bonding techniques whereas interfaces between silicon and glass wafers are bonded using anodic bonding techniques.

Abstract: Micromachining, etching and bonding techniques are employed to fabricate hermetically sealed gas-filled chambers from silicon and/or glass wafers. The hermetically sealed gas-filled chambers have precise dimensions and are filled with a preselected concentration of gas, thus rendering exceptional performance for use as an optical gas filter. The first step involves etching one or more cavities or holes in one or more glass or silicon wafers. These wafers eventually become part of a chip assembly having one or more hermetically sealed gas-filled chambers after appropriate bonding procedures. Interfaces between aligned silicon wafers are bonded using fusion bonding techniques whereas interfaces between silicon and glass wafers are bonded using anodic bonding techniques.

Abstract: A fluid flow sensor uses lift forces exerted on a plate-like airfoil member to determine the velocity of a fluid flowing past the sensor. The member has a pair of spaced, low aspect ratio airfoil elements. A central portion of the airfoil member is coupled to a frame that positions the airfoil member in the fluid flow with an angle of attack with respect to the fluid flow direction. The flowing fluid generates velocity related lift forces on the airfoil member, the magnitude of which decrease along the airfoil member from the upstream end to the downstream end. The lift forces so applied deflect the upstream airfoil element to a greater extent than the downstream airfoil element. Strain gauges are coupled to the airfoil elements to detect their deflection. The strain gauges are connected in a bridge configuration to provide a signal indicative of fluid velocity.