Atoms to Systems Lab

​​Background & Appointments

Prof. Derek Ho (何庆颂教授) is an Associate Professor in the Department of Materials Science and Engineering and a member of the Institute of Digital Medicine and the Hong Kong Institute for Clean Energy at City University of Hong Kong. He is also a cofounding co-principal investigator at the Hong Kong Centre for Cerebro-Cardiovascular Health Engineering, where his work focuses on translating soft sensing materials into wearable medical electronics. In 2022–2023, he was cross-appointed as a visiting professor in the Department of Materials Science and Engineering at Yonsei University in Seoul, South Korea.

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Prof. Ho received his B.A.Sc. (First-Class Honours) and M.A.Sc. in Electrical and Computer Engineering from the University of British Columbia, and his Ph.D. in Electrical and Computer Engineering from the University of Toronto in 2013. His doctoral research focused on integrating stimuli-responsive materials with microsystems for bioanalysis.

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Journey to Piezoionics

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In his own words:

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Throughout the 2010s, I observed a strong field-wide push toward truly stretchable sensors. Yet the available stimuli-responsive materials were predominantly rigid, and embedding them into soft polymer frameworks invariably forced trade-offs in performance and reliability. There appeared to be no active transduction mechanism native to soft matter itself.

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The COVID-19 lab closures offered an unexpected opportunity for deep reflection and literature exploration. During this period, I came across a 2000 paper by Nobel laureate P. G. de Gennes on mechanoelectric effects in ionic gels (Europhysics Letters, 50, 4)—the precise, fundamental mechanism I had been seeking: a force-induced ionic phenomenon intrinsic to soft, hydrated materials. That moment crystallized our lab's commitment to piezoionics.

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Fortunately, our group's prior work had laid the essential groundwork. We had already accumulated experience in both soft sensor development and electrochemical energy storage with polymer electrolytes—giving us a working foundation in the two pillars of piezoionics: transduction mechanisms and ionic conductive materials.

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Notably, piezoionics addresses two of society's grand challenges: healthcare and sustainable energy. It enables research that spans from fundamental science to practical application—a scope that aligns with my commitment to connecting novel concepts with meaningful real-world impact. Today, the lab is pursuing piezoionic devices for self-powered epidermal biosensors such as continuous blood pressure monitors and soft mechanical energy harvesters.

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For More Information

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Academic Genealogy (PDF)

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Interview with Materials Horizons, Emerging Investigator Series (DOI) (PDF)

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