Supervisor’s Foreword
Three-dimensionally seamless and noninvasive integration of electronics within
biological tissues could allow continuous monitoring and modulation of tissue
activities for applications ranging from tissue activity mapping to electronics-
enabled therapies. Previous studies have been only focused on placing tissue slices
on rigid electronic devices or coveringflexible electronics on tissue surfaces, which
have greatly limited the interface between electronic components with cells in the
interior space of tissues. This thesis describes Dr. Jia Liu’s fundamental research
results during his doctoral study in the Department of Chemistry and Chemical
Biology at Harvard University to answer the question of how to integrate elec-
tronics in a three-dimensionally seamless and noninvasive way within biological
tissues to build a direct electronics–cellular interface through the whole biological
tissue in vitro and in vivo.
Dr. Liu started his research with the design of nanoelectronic sensor arrays into a
three-dimensional (3D),flexible, and macroporous structure, which fully mimics
the structure of the extracellular matrix. He extended the contact printing method to
assemble synthesized silicon nanowires as nanoelectronic components on patterned
polymer structures and fabricated two-dimensional (2D) macroporous nanoelec-
tronics as precursors for 3D nanoelectronics. Dr. Liu designed the metal inter-
connects with internal strain, which, after being peeled-off from substrate, self-roll
up to reorganize the 2D nanoelectronic precursor into a 3D macroporous nano-
electronic network. Dr. Liu demonstrated that this 3D macroporous nanoelectronics
network could be integrated within conventional soft materials and functioned as
chemical, mechanical, and photonic detector arrays. The 3D nanoelectronics do not
alter the chemical and physical properties of those soft materials due to their high
porosity, nanoscale feature size, and ultra-flexibility.
Through the collaboration with Dr. Bozhi Tian, Dr. Liu designed macroporous
nanoelectronics into nanoelectronics tissue scaffolds (nanoES), combined these
nanoES with synthetic tissue scaffolds, and cultured synthetic tissues. The results
demonstrated a seamless and noninvasive interpenetration of synthetic cellular
networks with nanoelectronic networks. Dr. Liu demonstrated the 3D recording
of the synthetic tissues responses to the external drug stimulations and pH change.
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