With its wide bandgap of 3.4 eV, gallium nitride (GaN) is considered as a key semiconductor material for realizing ultra-low-loss power devices. However, GaN-based devices is still plagued by current collapse, which is the temporary reduction of current after application of electrical stress. In this work, we present the state-of-art Multi-Mesa-Channel (MMC) AlGaN/GaN HEMT being developed in our laboratory. The MMC HEMT is fabricated in a way to realize parallel mesa-shaped nano-channels separated by trenches. Investigations have revealed that the MMC HEMT is highly resistant to current collapse and other instabilities, making it a leading power electronics prospect.