The paper introduces a 24-channel air-trench isolated Silica-based VOA array. The air trenches thermally insulate the VOAs with etched-free waveguide technologies. Reactive ion etching and wet etching were used at different channel locations to suppress thermal crosstalk and reduce power consumption. https://www.nacrack.com/hot-savings-HiBoost-Home-15K-Smart-Link-F20G-5S-IoT-limited-super/