The present invention disclosed provides for a rugged, compact sensing device for various implementations including those of automotive, marine, and other combustion technologies that require low cost accurate pressure sensing during internal combustion engine process. The apparatus has a slicer for the slicing of potatoes, means for conveying sliced potatoes through a heated oil bath and for removal of cooked potato chips from the heated oil bath. The micro-lens array is formed from a master micro-lens array, which is placed within a replica micro-lens making assembly.