US Patent 11712204 Swallowable, food-based, digestible wireless device for measuring gastric pH

Systems and methods are presented for a swallowable pH sensor made entirely of edible and digestible materials. A substrate is provided and an electrical circuit pattern is printed on a top surface of the substrate. The electrical circuit pattern includes a plurality of interdigitated electrodes and an antenna portion. The substrate is rolled into a cylindrical form such that the interdigitated electrodes are positioned on an outermost layer of the rolled substrate. The rolling of the substrate also causes the antenna portion of the electrical circuit pattern to form into a coil shape.