Different Couplings Of Electrochemical Chip Sensors With Actuators In Microanalytical Fluidic Systems

A micromachined flow through assembly comprises three main parts: thin film platinum electrodes shaped as sub-/spl mu/m interdigitated arrays or parallel connected 2 /spl mu/m thin film platinum electrodes stacked or silicon/Pyrex channel plates and additional perpendicular arranged piezo injectors. Also, flow- through chambers of the single chip size have been used. Using interdigitated electrodes, flow profiles and flow rates have been measured by flow injection of ascorbic acid and, alternatively, by generating an electroactive species at one part of the array chip and collecting it after transportation to an other part of the array. Furthermore, a double FIA-system, where piezo injectors inject ferricyanide into flow diodes is shown to produce sharp separated FIA peaks.