Nature provides a range of examples where shape change is achieved through passive actuation
mechanisms, without the reliance on external sources of energy. One such example is the
response of hygroscopic materials, which undergo shape changes in response to fluctuations
in humidity. As Shape-changing interfaces have been critiqued for not being sustainable, incorporating these passive actuation mechanisms can offer benefits for the field of HCI. My research introduces chitosan as a biodegradable and humidity-responsive actuator, inspired by its hydro morphic transformation while focusing on exploring its utilization to support more sustainable approaches to haptic and shape-changing interaction. I contribute to the field of HCI by presenting a variety of responsive structures made from chitosan films, and the outcomes of generative sessions with a multidisciplinary team. I concluded the project with a variety of application possibilities.