“The common issue with [sensors based on ion selective membranes] is the leaching of ions from the internal electrolyte, causing the sensor to drift over time,” said Marcel Zevenbergen, senior researcher at imec/Holst Centre. “To suppress this, we designed and fabricated a reference electrode with a microfluidic channel as the junction and combined it with solid-state iridium oxide and silver chloride electrodes fabricated on a silicon substrate, as indicating electrodes for pH and Cl- respectively.”
According to Zevenbergen, tests showed the sensor offered a sensitivity, accuracy and response time equal or better than existing solutions.
John Baekelmans, managing director of imec in The Netherlands, added: “This multi-ion sensor is one in a series that Holst Centre is currently developing with its partners. For each sensor, the aim is to leapfrog the current performance of state-of-the-art sensors in a mass-producible, wireless, energy optimised and miniaturised package.”
