Poly (methyl methacrylate) (PMMA) were used as substrates in microcontact printing to ensure the cost-effectiveness for industry scale usability. The substrates were first functionalized with CO2 plasma treatment, depositing activated carboxyl groups and rendering the substrates hydrophilic to ensure maximal bioink transfer. The initial contact angle (CA) of untreated PMMA was 66.03°, indicating a relatively hydrophobic surface. By performing CO2 plasma treatment, for 3min to 15min, the CAs significant decreased to 55.7 o to 38.9 o , respectively, making the substrate sufficiently hydrophilic for μCP. Extending the plasma treatment to 30min caused the contact angle to drop further to 19.9°. We realized that this prolonged treatment resulted in over-etching, damaging the already formed carboxyl groups and ultimately reducing the effectiveness of covalent attachment during microcontact printing. Therefore, 15min plasma treatment was chosen as the optimum time to provide a degree of hydrophilicity while ensuring activated carboxyl groups remain on the functionalized PMMA substrates (Figure ).