Patent ID: 7879488

Claim:
An apparatus, comprising: a stack of substantially planar electrodes, the stack in alignment and having a stack form factor; a first planar housing portion including a first beveled edge at least partially defining a first stack aperture adapted to at least partially receive the stack, the first planar housing portion having a first portion having a first thickness proximal the first beveled edge, and a second portion having a second thickness greater than the first thickness, the second portion further away from the first beveled edge than is the first portion; and a second planar housing portion including a second edge defining a second stack aperture adapted to at least partially receive the stack, wherein the second planar housing portion is joined to the first planar housing portion such that they are substantially coplanar, wherein the first planar housing portion and the second planar housing portion define an interior space, the first planar housing portion and the second planar housing portion substantially conforming to the stack form factor, with the first portion of the first planar housing spaced orthogonally further from the stack than is the second portion of the first planar housing at a cross section of the first planar housing portion.