Designing and developing robots that can effectively navigate real-world environments poses a significant challenge. To overcome this, many robotic systems draw inspiration from the adaptive behaviors of animals, which have evolved to thrive in diverse surroundings. Amphibious animals, for instance, seamlessly transition between walking and swimming, optimizing their locomotion efficiency based on environmental cues. However, existing robots often face limitations in adapting to their surroundings, hindering their applications in crucial domains such as land and water search and rescue, natural disaster inspection, and environmental monitoring. This thesis seeks to contribute valuable insights into the enhancement of robot capabilities for applications demanding flexibility and efficiency in diverse, dynamic environments, and to address the aforementioned challenge by introducing innovative, stimuli-responsive robot legs made from bioplastic material onto a pre-existing low-cost, small-scale RHex robot system. These bioplastic legs enable the robot to dynamically adjust leg stiffness in response to environmental humidity levels, presenting a versatile solution for navigating various terrains. In the following thesis, we explored the material development, fabrication techniques, and manufacturing processes involved in creating the humidity-responsive robot legs. Following this, we also presented characteristic analysis of the bioplastic legs to explore their responsiveness to different durations of exposure to varying humidity levels. Finally, to evaluate the practical impact of humidity-responsive legs, four robot experiments were conducted to assess the RHex robot’s performance across different terrains. The results of these experiments demonstrate the advantages of humidity-responsive legs, showcasing their adaptability to specific terrains and environmental conditions.