3D microfluidic device fabricated by using surface-activated bonding of electroplated Ni patterns

We present a three dimensional (3D) microfluidic device fabricated by multiple-stacking of electroplated Ni patterns using surface-activated bonding (SAB) at room temperature. We successfully fabricated a micro heat exchanger as a feasibility device, which is 800 μm square by stacking nine layers of 25 μm-thick Ni patterns at alignment accuracy less than 1μm. 3D fluidic channels which consist of vertical holes of 100 μm diameter and horizontal paths 70 μm wide and 100 μm pitch were formed by simply stacking patterned Ni plates without any sacrificial layers.