What are some challenges in developing humanoid robots, and how do researchers address issues such as balance, stability, and human-robot interaction?

Challenges include designing humanoid robots with bipedal locomotion, dynamic stability, and human-like dexterity and flexibility. Researchers address these challenges through advances in robotics hardware, such as articulated joints and compliant actuators, as well as control algorithms for balance control, gait optimization, and natural interaction with humans.