Continuous and Sheathflow-Less Micro-/Nanoparticle Separation Combining Thermophoresis and THermoelectricity with a 3D Spiral Microchannel

Multiphysics separation is an emerging research field that has garnered considerable attention across diverse microfluidic applications. However, it has not been thoroughly explored due to the complex interplay of physical phenomena, and effective coupling between appropriate parameters is required depending on sample characteristics. Here, we introduce the Serpentine-spiral and Adjustable Radial Temperature (SART) device, a particle separation apparatus that utilizes both inertial effects and thermophoresis-based thermal diffusion. This study not only characterizes the separation of micro- and nanoparticles according to size through experimental validation but also demonstrates that the coupled effects enhance particle separation performance. The SART device, which can be flexibly operated under varying system conditions, shows promise in overcoming limitations imposed by particle and material properties, surface charge, and chemical interactions in both particle separation and microactuation applications.