A software-generated purchase verification key is generated and stored on a computer at the factory where the make-to-order computer is assembled. Specifically, the device includes a flexible substrate, a film of nanostructures in contact with the flexible substrate, a first conducting element in contact with the film of nanostructures, and a second conducting element in contact with the film of nanostructures. The first portion 16 has a first load bearing surface 42 and the second portion 18 has a second load bearing surface 50. The subframe portions may be processed to maintain a constant polarity by comparing a common sequence of data bits among at least two of the subframe portions to identify a mismatch in polarity. A number of interconnects between the ROIC and the detector array can be less than one per light sensor or pixel. The slots are elongate to accommodate different sized chairs having feet spaced at varying radial dimensions.