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Cell substrates play a crucial role in tissue engineering and biomaterial science. Various studies are performed to develop the appropriate cell substrates for using in vitro and in vivo. Therefore, a biocompatible substrate that mimics the native extracellular matrix properties with specified surface topography as a biomimicry factor is necessary under ''the novel cell substrates development'' approaches. Our aim in the current study was to design, synthesize, and characterize a substrate with aligned nanometric arrays on the surface. The rapid and easy capabilities of Polydimethylsiloxane to receive chemical and physical characteristics with simple modifications, make it a promised candidate for the cell substrate. The obtained results from the atomic force and scanning electron microscopy showed the formation of 305±19 and 571±141 nanometers wrinkled nanoarrays after regulating the substrate under lateral traction during the plasma treatment times of 100 and 200s. Then, the behavior of a human foreskin fibroblast cell, in terms of adhesion, growth, viability, and morphology on this substrate was investigated. Increasing the plasma treatment time increased both nanoarray size and surface hydrophilicity, resulting in improved 17 and 46% of cell attachment quality, respectively. Additionally, the presence of the designed nanowrinkles surprisingly improved the number of the attached cells. The nanowrinkles caused the cells to align perfectly through the substrate's surface due to the contact guidance phenomena. Consequently, the biocompatible Polydimethylsiloxane substrate of this study with suitable chemical, mechanical, and physical properties showed fit capacities as a novel aligned cell culture platform. 

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In recent years, forming a 3D microfluidic channels on the electrical non-conductive material such as Polydimethylsiloxane (PDMS) in the micro-electromechanical system (MEMS) and medical applications is of great interest. Lithography is the most know process to create patterns on the PDMS however there are a few drawbacks to this process such as high operational cost and time, and sidewall angle. In all applications, the quality of the microchannel surface determines the performance of it. In this research as innovatively the electrochemical discharge milling (ECDM) which is known for lower operational cost and proper material removal rate (MRR) (i.e. process time), and is capable of creating patterns on electrical non-conductive material, was used to form a microchannel on the PDMS. To that end, the effect of process parameters such as electrolyte concentration, feed rate and cutting speed and voltage on the surface roughness and surface integrity deeply investigated. It was observed that ECDM is capable of creating patterns on the PDMS with surface integrity which is comparable with the lithography microchannel. It is also observed that decreasing the rotational speed from 10000 to 0 rpm results in increasing the surface roughness 2 to 4 times, this happens due to the increasing the thickness of the gas film around the tool, and subsequently increasing the flying sparks which results in higher surface roughness. Increasing the Voltage from 38 to 42 V results in 38% enhancement of surface roughness. The 25% electrolyte concentration results in lower surface roughness.