Low-cost implementations of pH monitoring platforms

Real time monitoring of electrolytes is nowadays of paramount importance, especially for biomedical applications and clinical assays. Although chemical sensors can be implemented in conventional CMOS technologies, enabling the monolithic integration of read-out and processing circuitry with sensor cells that follow Moore´s scaling, a vast number of challenges often prohibit their practical application. In this paper we describe a design methodology for facilitating chemical sensing platforms that are low-cost, disposable, reliable, robust and easy to integrate within any environment. We employ a hybrid approach in that the passive elements of the sensors are fabricated in a customized technology while the active transducers are based on off-the-shelf components. Here we specifically demonstrate this technique for establishing a H⁺ sensing platform for monitoring pH.