{
    "protocol": "A regular micro-pillared array (MPA) was designed using a PDMS film (PF) in combination with silicon dioxide (SiO2) modification. An SU-8 mold of negative well arrays was obtained using traditional UV lithography. A soft replication method was adopted to obtain a PF with MPA as the substrate. SiO2 nanometer coatings were then sprayed on the surface of the PF with the MPA. The dimensional uniformity and quality of the prepared PF were characterized using field emission scanning electronic microscopy (FESEM). Fourier transform infrared spectroscopy (FTIR) indicated the presence of functional groups -CH2 and -CH3 on the surfaces of the bioinspired PF samples.First, clean glass slides (approximately 4x3 cm^2) for 10 min. Dry the substrate at 200°C for 30 min. Dispense SU-8 photoresist on the glass slide through a spin-coating program at 500 rpm for 10 s and 3000 rpm for 30 s. Soft bake the substrate on a level hotplate at 103°C for 6 min. Perform traditional UV lithography with UV exposure (exposure energy at 158 mJ cm^-2 for 10 s) perpendicularly to a photomask of circle-shaped array patterns. Carry out a post exposure bake step at 98°C for 5 min to harden the SU-8 layer. The thickness of the resulting film is approximately 6 μm. Lastly, immerse the substrate in the developer for 30 s and agitate the solution using a tweezer to obtain the uniform SU-8 CMHA on the glass substrate.First, the prepolymer and the curing agent were mixed uniformly and stirred in a glass beaker to synthesize the PDMS. Second, the PDMS was poured over the photoresist layer gently and the assembly was moved into the vacuum chamber for 40 min to remove air bubbles, next it was heated in a drying oven at 80 °C for 1 h to completely cure the PDMS. Last, the solidified PDMS was peeled off from the glass substrate and the MPA was transferred to the PF.A commercial SiO2 coating agent was sprayed on top of the as-prepared PDMS using a spray coating setup at a distance of approximately 15 cm from the nozzle head. The samples were then baked in a drying oven at 80 °C for 20 min. The spray coating and heating processes were repeated twice."
}