Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance upgrade on Thursday 4th of May 2017 from 8.00am to 9.00am (BST).

During this time our websites will be offline temporarily. If you have any questions please use the feedback button on this page. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 6, 2014
Previous Article Next Article

Real-time feedback control of pH within microfluidics using integrated sensing and actuation

Author affiliations

Abstract

We demonstrate a microfluidic system which applies engineering feedback principles to control the pH of a solution with a high degree of precision. The system utilizes an extended-gate ion-sensitive field-effect transistor (ISFET) along with an integrated pseudo-reference electrode to monitor pH values within a microfluidic reaction chamber. The monitored reaction chamber has an approximate volume of 90 nL. The pH value is controlled by adjusting the flow through two input channels using a pulse-width modulated signal applied to on-chip integrated valves. We demonstrate real-time control of pH through the feedback-controlled stepping of 0.14 pH increments in both the increasing and decreasing direction. The system converges to the pH setpoint within approximately 20 seconds of a step change. The integration of feedback theory into a microfluidic environment is a necessary step for achieving complete control over the microenvironment.

Graphical abstract: Real-time feedback control of pH within microfluidics using integrated sensing and actuation

Back to tab navigation
Please wait while Download options loads

Publication details

The article was received on 24 Oct 2013, accepted on 23 Jan 2014 and first published on 23 Jan 2014


Article type: Paper
DOI: 10.1039/C3LC51205C
Citation: Lab Chip, 2014,14, 1191-1197
  •   Request permissions

    Real-time feedback control of pH within microfluidics using integrated sensing and actuation

    D. Welch and J. B. Christen, Lab Chip, 2014, 14, 1191
    DOI: 10.1039/C3LC51205C

Search articles by author