Streamlining Microfluidic Lithium Sensor Fabrication: A Single-Workflow Using Additive Manufacturing and Printed...

Area of Science:

• Electrochemistry
• Materials Science
• Sensor Technology

Background:

• Integrated microfluidic electrochemical sensors typically involve complex, multi-step fabrication processes.
• Current devices struggle to seamlessly integrate electrodes, surface chemistry, and fluid handling.

Purpose of the Study:

• To develop a unified additive manufacturing approach for fabricating microfluidic electrochemical sensors.
• To enable direct formation and functionalization of laser-induced graphene (LIG) electrodes within a single workflow.
• To demonstrate ion-specific sensing capabilities, exemplified by lithium detection.

Main Methods:

• Utilized polyetherimide (PEI) for additive manufacturing, enabling direct laser-induced graphene (LIG) electrode formation.
• Functionalized working electrodes (WEs) by printing lithium manganese oxide (LMO).
• Additively manufactured microfluidic channels on the same platform, preserving a single-workflow process.

Main Results:

• The integrated microfluidic sensor demonstrated enhanced sensing performance, with a 31.6% increase in reduction peak compared to a non-microfluidic baseline.
• Achieved a wide dynamic range (0.01-10 M) suitable for lithium extraction and monitoring.
• Exhibited high specificity and selectivity for lithium detection in the presence of interfering ions, with LOD of 9.5 mM and LOQ of 148 mM.

Conclusions:

• Additive manufacturing offers a practical and streamlined route for producing LIG-based microfluidic electrochemical sensors.
• The developed method simplifies fabrication while enhancing sensor performance for targeted ion detection.
• The sensor is well-suited for applications requiring precise lithium monitoring and extraction.