A Single-Solvent Acetone Strategy for Surface Enhancement and Robust Bonding in PMMA Microfluidic Devices

Abstract

Microfluidic technologies enable portable, low-volume, and cost-effective diagnostic platforms, yet their widespread adoption remains limited by fabrication complexity and reliance on cleanroom infrastructure. Polymethyl methacrylate (PMMA) is an attractive material due to its optical transparency, biocompatibility, and affordability; however, conventional fabrication methods such as laser engraving and micromilling often induce surface roughness and defects that compromise device performance. Here, we present a single-solvent strategy that utilizes pure acetone as both a surface enhancement and bonding agent for laser-ablated PMMA. Controlled acetone treatment combined with thermal conditioning transforms rough, damaged channel surfaces into smooth, optically clear interfaces. Subsequent acetone-assisted bonding enables the formation of uniform, high-strength interfaces without additional reagents or complex processing steps. The resulting microfluidic channels exhibit surface properties comparable to bulk PMMA and achieve bonding strengths up to ∼27.3 MPa, approaching the intrinsic tensile strength of the material. The method supports channel dimensions as small as 88 µm × 132 µm and demonstrates excellent mechanical stability under high centrifugal forces with reliable sealing performance. This approach provides a rapid, scalable, and cost-effective route for fabricating high-performance PMMA microfluidic devices, substantially lowering barriers to broader adoption.