Department of Applied Physics and Materials Science - Materials Science

Research

We seek to understand and control the world of solids, liquids, and gases around us. Traditional materials science has a focus on "engineering materials" of technological importance such as ion conductors or doped silicon. At Caltech we also develop engineering materials and devices as we see opportunities, but we also try to control the stability of crystals under pressure or temperature, for example. A rigorous emphasis on basic science and mathematics backs up what we do.

Research Areas

Biomedical Devices

  • Developing nanomaterials-based flexible and wearable sensors for personalized health monitoring. (Gao)
  • Studying micro/nanoscale active colloids and motors for biomedical applications such as rapid drug delivery. (Gao)

Ceramics and Composites

  • Researching ceramics that maintain strength and robustness to temperatures in excess of 1500°C. (Faber)

Computational Materials Science

  • Investigating electrons in materials with Angstrom space and femtosecond time resolutions, with applications in energy conversion, novel electronics and optoelectronics, and ultrafast spectroscopy. (Bernardi)
  • Creating new materials and the optimization of materials processing. (Bhattacharya)
  • Computing the free energy of materials at the level of atoms and electrons. Calculating the stabilities of material phases, and properties such as thermal expansion, elastic moduli and thermal conductivity. (Fultz)
  • Studying the electronic noise of hot electrons under non-equilibrium conditions using ab-initio methods, with applications in low-noise semiconductor devices. (Minnich)

Energy Materials and Storage

  • In collaboration with the Joint Center for Artificial Photosynthesis, we are researching how to build an efficient, fully-integrated photoelectrochemical (PEC) device for the production of renewable fuels including hydrogen (near term) and hydrocarbons (long term). (Atwater)
  • The creation of new scientific instrumentation using ultrafast X-ray and AC electrical pulses to understand transport and storage in a range of material classes. (Cushing)
  • Developing thermal and environmental barrier coatings for power generation components to enhance engine efficiency via characterization of plasma-sprayed coatings. (Faber)
  • Generating new materials that store hydrogen by surface physisorption or internal chemisorption, with an eye towards applications in rechargeable batteries, fuel cell vehicles, and a collaboration with JPL on a possible future mission to the planet Venus. (Fultz)
  • Developing next-generation battery materials from sustainable resources and probing their charge storage mechanisms. (See)
  • Developing and optimizing doped graphene nanomaterials as anodes for energy storage applications in supercapacitors and lithium-ion batteries. (Yeh)

Metamaterials and Metasurfaces

  • Investigating electromagnetic metamaterials which are artificial materials comprised of nanostructures, with special interest in two of the most famous theoretically predicted optical functionalities of metamaterials: epsilon-near-zero and negative index metamaterials. (Atwater)
  • Designing and characterizing phononic metamaterials, which are structured materials with specific architectures, selected to control sound, ultrasound and stress waves in solids. Study of fundamental phenomena to advance RF telecommunication systems, sensors and medical technology. (Daraio)
  • Designing plasmonic vortices based on nanoscale metal-dielectric-metal (MDM) meta-structures to control the opto-spintronic, opto-valleytronic and topological excitations in monolayer transition metal dichalcogenides. (Yeh)

Nanostructures

  • Studying the quantum properties of surface plasmons both for fundamental insights into their physics as well as for applications in quantum information science. (Atwater)
  • Investigating microwire solar fuel devices which have the potential to replace fossil fuels. (Atwater)
  • Building artificial materials and heterostructures on the nanoscale using thin film deposition techniques. (Falson)
  • Creating extremely strong yet ultra-light materials by capitalizing on the hierarchical design of 3-dimensional nano-architectures. (Greer)
  • Developing and applying the atomic layer etching process for nanofabrication, which permits the removal of a monolayer of material with atomic precision. (Minnich)
  • Developing “quantum straintronics” by nanoscale strain engineering of van der Waals materials (e.g., graphene, hexagonal boron nitride, transition metal dichalcogenides) to achieve strain-controlled properties such as bandstructures, electronic correlation, optical bandgaps, and superconductivity. (Yeh)

Photovoltaic Materials and Devices

  • Designing and building a spectrum-splitting photovoltaic module that will achieve unprecedentedly high efficiency, as well as investigating several alternative materials that can potentially replace or complement traditional silicon photovoltaics. (Atwater)
  • Pushing towards simultaneous femtosecond / angstrom resolved, electron and X-ray spectroscopies for studying interfaces and photoexcited processes in photovoltaic materials. (Cushing)

Polymers

  • Developing stimuli-responsive polymers with a focus on molecular design. (Robb)

Organic Electronic Materials

  • We study biological structures and compounds, to create new, synthetic polymers for temperature and IR sensors, and other engineering applications. We analyze their molecular architecture and tailor their properties, to optimize their sensing performance and add functionalities. (Daraio)

Thermodynamics and Phase Transformations

  • Studying emergent electronic and magnetic phases in correlated materials in extreme environments including low temperature and high magnetic field. (Falson)
  • Conducting neutron and x-ray inelastic scattering experiments to understand how entropy changes with pressure and temperature, and for measuring local atom distortions during the diffusive jumps of hydrogen atoms in materials. (Fultz)
  • Investigation of unconventional superconductors with such novel properties as unconventional pairing symmetries, strong electronic correlation, non-trivial topology, and pressure-induced superconductivity. (Yeh)