Figure 2.

Characterization of the polydimethylsiloxane (PDMS) channels and magnetic polycaprolactone (PCL)/Fe₃O₄ assymetric billet. (A) Scanning electron microscopy (SEM) images of the cross‐section of PDMS channels fabricated with different printing speeds using 0.9 mm needles. (B) The width and depth of the channels against the printing speeds. (C) SEM images of the cross‐section of assymetric PDMS channels with designed shapes. (D) Optical microscope image of channel 2. (E) SEM image of magnetic PCL/Fe₃O₄ assymetric billet from channel 2. The values of speed were marked on each image and the unit was mm min⁻¹. (Mean ± standard deviation (SD) from n = 5 different samples fabricated under same condition).