CAREER: Material-Changing Interfaces

People interact with materials all the time. Typically materials are used for specific purposes, for example, wood to hold up rigid floors or foam for cushioning. These materials do not change their properties as people interact with them.

While a rigid floor is great for walking, cushioning properties would be desirable to prevent injuries if a person falls. This project will develop materials that can change their properties to adapt to people and their actions. Generally, materials consist of microscale structures.

For example, looking very closely at foam materials that are often used for packaging reveals that they consist of many tiny randomly oriented struts. This project will generate strategically oriented struts to perform a desired deformation when people interact with it. In the floor example, structures that soften upon a large impact, such as a person falling, will be generated.

Similarly, material structures to provide ergonomic support can be computed, such as a chair cushion that becomes thicker in the back when people sit down to promote an upright posture. Such materials can also be tailored to people's bodies, for example, as assistive braces for rehabilitation that can adapt their stiffness with every step.

The scientific aims of this project are to understand when and how users will interact with such adaptive materials and how to design and fabricate them. Materials governed by their microstructures (also known as mechanical metamaterials) with designed bulk behavior have been investigated in engineering disciplines yet a deeper understanding of their human-centered qualities is missing, for example, their capabilities for interaction, user needs, or utility.

To approach such interactive passive materials systematically, this project will address three classes of challenges. The first challenge is understanding how users will interact with the materials. The second challenge is developing advanced computational design tools that optimize new structures and allow them to be shared, evaluated, and reused.

The final challenge is the long-term integration and in-depth user evaluations of applications. The project will first create a robust analysis of application domains and user evaluations of initial prototypes, resulting in a new design space that characterizes the material-changing interfaces. Based on these findings, libraries of structures and computational design tools will be built to foster a growing repository of designs and associated performance evaluations, enhancing collaborative opportunities and innovation in the field.

With this foundational framework, design tool, and evaluation protocols, application areas will be investigated in-depth.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.