UC San Diego

In applications such as search-and-rescue and minimally invasive surgeries, as well as devices for aerospace (e.g., solar panels), there is a need for lightweight, deployable, compact, and scalable systems. Traditional robots made of rigid parts have been explored for repetitive tasks in industrial settings or daily tasks such as cleaning. However, is still challenging to achieve less bulky or ubiquitous solutions as observed in nature to morph and adapt their shapes given an environment or need. For instance, organisms such as ladybugs, pinecones, and jumping gal maggot fleas have achieved mesoscale morphability via folding or compliance of their body for locomotion and survival.

Inspired by nature, self-folding and soft robots have been developed by exploring the intersection between rapid fabrication and soft materials. However, it is still challenging to achieve mesoscale actuation that can be easily integrated to these systems while still leveraging their advantages towards compact, lightweight, scalable, and deployable robots. For instance, traditional motors (e.g., electromagnetic motors) enable simple and accessible integration with other electronic parts to achieve autonomous robots. Despite that, they are not simple to pattern (i.e. adapt its shape), to scale (i.e. size), and to integrate with soft materials and rapid fabrication methods. In the intersection of these desired features lies the opportunity to explore actuation methods and system designs using smart materials that inherently respond to stimuli and behave as artificial muscles.

In this thesis, I propose to leverage the advantages of smart materials to achieve patternable actuation for mesocale self-folding and soft robots. When combined with lightweight composite mechanisms, these smart material actuators enable new types of lightweight, compact, and modular robots. First, I propose an approach that explores the artificial muscle liquid crystal elastomer (LCE) advantages with rapid fabrication techniques towards reversible self-folding composite hinges. Second, I develop a new methodology to achieve reversible, lightweight, modular, and patternable self-folding machines with a single layer of LCE. Then, I focus on the challenge of amplifying the power output of artificial muscles that offer desirable features for mesoscale actuation but are inherently slow. To achieve this power amplification, I developed a modular system with a nonlinear elastic element to slowly store energy, and release it rapidly when triggered by a latch mechanism.

This work lays the foundation for applications that go beyond mesoscale actuation—for instance, exploring these methodologies that combine smart materials with composite mechanisms towards embodied computing, sustainable robots, and interactive systems.