Saturation Trails acid assay - Stephen Cornford, 2017

Saturation Trails seeks to reveal the architecture of the digital image through direct material interaction with image sensors, the now ubiquitous photosensitive semicondcutors which transduce light into voltage in our digital cameras. The project appropriates three techniques from optoelectronic manufacture and testing: pulsed lasers, acid etching and x-ray radiation. The silicon substrate of image sensors is highly inert and can only be etched with hydroflouric acid, which is used to lay down the conductive microelectronic architecture of the chip during manufacture. The exposure of a sensor to acid produces a liquid photogram on its surface which gradually reveals its layered structure: wrinkling the polyamide coating before attacking the pixel structure of the image. The different readout patterns of CCD and CMOS chips become visible in the geometric patterns produced during etching. During these acid tests the machine eye hallucinates colours which have no referrent in optical reality.