Related Experiment Video
Updated: Jun 12, 2026
09:10
Fabrication and Testing of Microfluidic Optomechanical Oscillators
Published on: May 29, 2014
Roll-to-Roll Gravure-Printed SWCNT Ring Oscillator for Flexible Microfluidic Ion Sensing
Junfeng Sun1, Hyejin Park2, Jinhwa Park2,3
1Research Center for Advanced Electronics Manufacturing, State Key Laboratory of Intelligent Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Nanomaterials (Basel, Switzerland)
|June 11, 2026
Summary
We developed a flexible, printed microfluidic ion sensor using single-walled carbon nanotubes (SWCNTs). This scalable technology enables accurate, non-contact ion sensing for wearable healthcare and lab-on-a-chip devices.
Area of Science:
- Materials Science
- Electronics
- Nanotechnology
Background:
- Scalable, accurate ion sensing is crucial for flexible healthcare and lab-on-a-chip applications.
- Existing ion-sensitive transistor platforms often lack scalability and require complex setups.
Purpose of the Study:
- To present a fully roll-to-roll (R2R) printed, flexible microfluidic ion sensing platform based on single-walled carbon nanotube complementary ring oscillators (SWCNT-cROs).
- To demonstrate frequency-based ion sensing via electrostatically induced top-gating in aqueous environments.
Main Methods:
- Fabrication of SWCNT-cRO devices using R2R gravure printing on a flexible substrate.
- Utilizing printable n-doping technology for complementary SWCNT transistor operation.
- Integration with polydimethylsiloxane (PDMS) microfluidic channels for ion concentration and pH modulation.
Main Results:
- Achieved stable SWCNT-cRO oscillation characteristics with high device yield (>80%) and continuous manufacturing capability.
- Demonstrated systematic modulation of oscillation frequency by Na+ concentration and pH.
- Sensing mechanism identified as electrostatically induced carrier modulation in n-type SWCNT transistors.
Conclusions:
- The proposed SWCNT-cRO platform offers scalable manufacturing, non-contact sensing, and eliminates the need for external reference electrodes.
- This technology is compatible with digital frequency-signal processing, paving the way for low-cost, disposable flexible microfluidic sensors.
- Establishes a promising strategy for wearable healthcare, lab-on-a-chip devices, and advanced thin-film transistors.
