Using latent heat of vaporization, the two-phase heat transfer has been used in a variety of industries to remove surface heat and improve surface performance. The hydrophilic and hydrophobic properties of each phase can improve the boiling. The surfaces with mixed wettability (biphilic) can more effectively control bubble dynamics and boiling heat transfer. The width and the pitch of the rectangular hydrophobic pattern on a copper surface were parametrically optimized through experimental tests. Surface modification was accomplished by combining two methods of electrospray deposition and photolithography. The nucleation sites, bubble departure diameter, and surface rewetting were controlled by adjusting the width and pitch of hydrophobic patterns. The samples were explored by energy dispersive X-ray spectroscopy (EDX), profilometric analysis, and scanning electron microscopy (SEM). In addition, an experimental correlation was established for the heat transfer coefficient (HTC) at a width range of 0.5–3 mm and a pitch range of 1–3 mm. For a better understanding of related heat transfer, bubble visualization was achieved utilizing a high-speed camera system. In the best case, the maximum heat flux (MHF) and HTC increased by 130.2 % and 140 % compared to the plain copper surface, respectively.
