The Betwixt and the Between: Caroline Baillie's Journey Across the Interfaces of Materials, Justice and Education

In Fall 2025, Professor of Integrated Engineering, Caroline Baillie, PhD, was awarded the University Professorship at the University of San Diego — the highest academic honor bestowed university-wide. This recognition of her academic achievements prompted an in-depth conversation, the synthesis of which reveals an inspirational journey from materials science to global social justice.

A highly cited academic, Baillie is a world-renowned pioneer within the field of engineering and has dedicated her career to dismantling the notion that engineering is solely a technical discipline, insisting that it is also a powerful sociotechnical force. 

Fueled by an early curiosity about how the world works, her journey began with a foundation in materials science and engineering, where she focused on composite materials and plastics. While technically proficient, she found herself increasingly at odds with the ethical dimensions of corporate and industrial priorities. She began to ask critical questions about the environmental and social impact of her research.

The most definitive early experience that set her trajectory involved her first job in public relations after her undergraduate degree. “I resigned when I was asked to promote asbestos,” Baillie admits. This moment established a clear boundary: she would not use her professional skills to ignore known harm. 

This "overdeveloped social conscience," as she describes it, compelled her to return to academia for a PhD and eventually transition her focus to engineering education, constantly asking: “How can technical knowledge be harnessed for the greater good?” This shift from the mechanics of polymer composites to the justice for vulnerable populations formed the bedrock of her life’s work.

Baillie's path to becoming a materials scientist was globally inspired. Her travels in the 1990s, began with a backpacking trip in Australia. “I met a boat builder working with fiberglass, who introduced me to a fiberglass company in Sydney,” recalls Baillie. This connection led to the topic for her PhD and many other rhizomatic pathways, and some years later led to a transdisciplinary art exhibition in Berlin, which focused on the interface inside reinforced plastic — "the bit that’s between the plastic and the fiber." This concept of "the betwixt and the between," as she calls it, became a lifelong fascination of serendipitous interfaces that flowed through her professional decisions. 

An example of that place “betwixt and between” was her early work in biomimicry. She was introduced to biomimicry by her professor at the University of Sydney, Yiu-Wing Mai, PhD, in 1993, before the term was used widely across the world —  an intriguing interface between nature and engineering. By mimicking nature, engineers study how nature solves its inherent problems and apply those concepts to engineering principles. 

“Everyone was talking about smart materials that behave more like nature,” she explains. “One example was the skin of the Airbus aircraft. The idea was modeled after the movement of sharks. It allowed the aircraft to move more swiftly through the air. You could do the same with air resistance to reduce the amount of fuel that was used.”

Baillie's professional journey expanded beyond the physical realm of reinforced plastics to encompass the interface between engineering and education. This shift was sparked while she was teaching in Sydney, where she noticed the severe lack of female students in her mechanical engineering classes. 

Driven to understand this gender disparity and improve her pedagogy, she pursued a master’s degree in higher education. “I did this to learn how to teach — they don’t require you to learn how to teach in academia,” Baillie observes. She focused specifically on gender inclusivity for her thesis and explored the question: why so few? (women in engineering). This research revealed a crucial insight from one of her female students: "Thank you for listening to me, I had no idea I could be me and be an engineer."

Her realization that changes were necessary in both the way engineering was taught and the profession itself led her to pioneer a new, hybrid field. “At the time, I was only 1 of 5 people in the world who called what I did engineering education in the 1990s.” Despite pressure to choose one discipline, she embraced her hybrid existence, blending her expertise in physical interfaces with the interfaces of learning.

This dual focus led her to research threshold concepts, “tricky and troublesome knowledge areas, like a vector in mathematics,” that act as conceptual passageways students must cross to truly master engineering. Baillie's research identified that adopting a socially just perspective is itself a significant threshold that students and practitioners must cross.

It's troublesome because it forces the reconciliation of technical, analytical demands with broad moral and political critiques. “Students often struggle with their perceived roles as engineers and the value of learning, finding it difficult to connect abstract science to real-world ethical dilemmas.” By identifying this transition as a threshold, Baillie provides educators with the tools to design curricula that intentionally guide students through intellectual hurdles, foster creativity and prioritize the well-being of people and the planet, ensuring their creations serve humanity rather than enslave it.

Baillie draws a crucial distinction between corporate social responsibility (CSR) and social justice in engineering, arguing that CSR risks being a “superficial, tick-a-box" effort designed to preserve the status quo. In contrast, social justice demands a transformative critique of power systems, compelling engineers to ask radical questions about the dominant systems and justice across economic, social and environmental domains. By insisting on justice, Baillie urges the profession to move beyond simple technical efficiency and engage in work where the core goal is actively reducing disparities, promoting equity, restoring reciprocity and ultimately favoring people and the planet over profit.

The Engineering, Social Justice and Peace (ESJP) network was co-founded by Baillie in 2004 to provide an international platform for academics, students and practitioners to focus explicitly on the connections between engineering, justice and peace. It advocates for a new paradigm in engineering education, and in engineering practice, one that integrates these values at a foundational level. 

Inspired by the intersection of material science and environmental justice, Baillie then co-founded Waste for Life (WFL) in 2006 with her husband Eric Feinblatt — seeing waste not as an end product but as a mismanaged resource. The organization's mission is to share engineering knowledge with those who would not normally have access to such knowledge by supporting the development of community run waste-based businesses. They teach community groups to create low-cost composite material products from locally found waste plastic and fiber using adapted hot-press technology. 

Three long-term projects have supported the nucleation of many waste-based businesses (mostly women led): in Argentina (2007-2014) where communities of cartoneros (urban recyclers) were suffering from an economic collapse; in Sri Lanka (2013-2018) following the destitution of civil war; in Mexico (2018-2025) with those living in informal housing close to the U.S. border, with no services, just garbage and pigs on the streets for the kids to play with.

Following Baillie’s arrival at USD, she shared her experience of sharing knowledge through WFL and the European science shops, knowledge brokering model. This led to the formation of the Engineering Exchange for Social Justice (ExSJ), which provides a formal structure for local community groups and non-profits to bring their problems directly to the university. This ensures that academic research is relevant, immediately applicable to local social justice needs and is co-created with the community.

Today, Baillie is the academic director of the Master of Science in Engineering, Sustainability and Health (MESH) program at the Shiley-Marcos School of Engineering. MESH is Baillie's answer to the narrowness of traditional engineering education, and is built on the profound conviction that global challenges — disease, poverty, climate change — are inherently transdisciplinary. “MESH rejects disciplinary silos. It trains students to develop solutions through a critical, transdisciplinary lens, integrating complex systems approaches to health and sustainability,” explains Baillie.

She adds, “MESH is designed to produce compassionate professionals who are not only excellent in their own domains, but are equipped with the capabilities and critical frameworks necessary to co-create just and holistic solutions.

Baillie calls for a fundamental, internal shift in the engineering community. It means moving away from a mindset focused solely on speed and efficiency to one rooted in compassion and sustainability. 

Caroline Baillie's pioneering work — culminating in the University Professorship — is a testament to her lifelong mission: redefining engineering not as a purely technical exercise, but as a force for justice and sustainability. Through her revolutionary work, she has consistently built bridges across the interfaces of matter and morality. Her legacy is a powerful call for a "revolution of the heart," urging a new generation of engineers to embody compassion, embrace complexity and fundamentally prioritize people and the planet in the relentless pursuit of a just and equitable future.

— By Michelle Sztupkay