Materials research concerns the development of engineering materials for technological needs, which pertain to the aerospace, automotive, transportation, civil infrastructure, electronics, medicine, energy, environment, sustainability, manufacturing, and control sectors.
A. Pioneer and the foremost international leader in the field of multifunctional structural materials (without device incorporation), with the following specific contributions.
- Invention of smart (self-sensing) concrete and associated development of piezoresistivity-based strain sensing in cement-based and carbon fiber composites.
- Discovery of the function of the interlaminar interface in carbon fiber polymer-matrix composites as a sensor, thus enabling unprecedentedly high sensitivity to changes at this damage-prone interface.
- Development of the self-sensing in carbon fiber polymer-matrix composite beams under flexure by surface resistance measurement, with the strain at the tensile and compressive surfaces separately and sensitively determined, and with the piezoresisitivity mechanism elucidated.
- Development of capacitance-based self-sensing, with applications including 3D-printing monitoring (with unprecedented ability of sensing interlayer defects in the build).
- First report of structural capacitors (i.e., capacitors in the form of structural materials).
- Pioneering the emerging field of high-permittivity electronic conductors, first determination of the electric permittivity of electronic conductors (carbons and metals), discovery of ferroelectricity in a metal, and discovery of the application in electret-based self-powering (with unprecedented self-charging capability), with the latter discovery allowing structures to be energy sources (a new untapped source of energy), and with elucidation of the dielectric behavior in terms of the carrier-atom interaction (carrier meaning the mobile charges).
- Discovery of interface-derived viscoelasticity and the consequent unprecedented development of structural materials that are effective for vibration damping.
B. Pioneer and the foremost international leader in the field of thermal interface materials for microelectronic cooling, with the following specific contributions.
- Changing the paradigm of the design of thermal interface materials from thermal-conductivity-based design to conformability-based design, thereby resulting in the development of superior but low-cost thermal interface materials that excel due to conformability.
- Development of unprecedentedly effective thermal pastes with conformable solid components.
C. Pioneer and the foremost international leader in the field of materials for electromagnetic interference (EMI) shielding, with the following specific contributions.
- Changing the paradigm of the design of EMI shielding materials from electrical-conductivity-based design to interface-area-based design, thereby resulting in the development of an unprecedentedly effective EMI shielding material in the form of nickel-coated carbon nanofiber (originally known as nickel filament).
- Discovery of absorption-dominated EMI shielding in metals, the shielding of which has long been assumed to be dominated by reflection.
- Discovery of unusually high EMI shielding effectiveness in exfoliated-graphite-based flexible graphite sheets, which are valuable for EMI gasketing.
- Development of radio-wave reflective concrete and its application in automobile lateral guidance.