Catherine Crichton1,Elliot Strand1,Juan Pablo Cisneros Barba1,Nicholas Bruno1,John-Baptist Kauzya1,Anupam Gopalakrishnan1,Madhur Atreya1,Eloise Bihar2,1,Gregory Whiting1
University of Colorado Boulder1,University at Buffalo, The State University of New York2
Catherine Crichton1,Elliot Strand1,Juan Pablo Cisneros Barba1,Nicholas Bruno1,John-Baptist Kauzya1,Anupam Gopalakrishnan1,Madhur Atreya1,Eloise Bihar2,1,Gregory Whiting1
University of Colorado Boulder1,University at Buffalo, The State University of New York2
Soil pH significantly affects agriculture by regulating available nutrients and water-soluble chemicals available to plants, thus driving the need for low-cost, durable soil pH sensors. A few potential solutions include expensive commercial pH sensors and printed sensors that only work in liquid media. Each of these solutions poses its own set of unique challenges perpetuating the affordable soil pH sensing dilemma. Here, we present a novel pH sensor platform based on an array of low-cost, durable, screen-printed electronics for in situ soil sensing. We show the stabilization of the pH-sensitive dye, alizarin, in the printed pH devices allowing for extended sensing periods in soil. We compare different alizarin dye immobilization techniques and electrode configurations and have evaluated the effects of soil pH on sensor durability. This new affordable, stable printed pH system pioneers the development of printed electronics for new alternatives to assess soil pH.