News Articles & Press Archive

The combination of multiple periodic structures to create moiré patterns holds great potential for controlling and manipulating light. However, the effects and interactions associated with moiré patterns have been limited to the immediate vicinity of these patterns....

Nanoparticle shape plays an important role in targeted drug delivery. Investigations of how differences in morphology affect nanoparticle-cell interactions at the single-particle level—especially internalization and cellular trafficking—are critical yet limited. Using...

The tailored spatial polarization of coherent light beams is important for applications ranging from microscopy to biophysics to quantum optics. Miniaturized light sources are needed for integrated, on-chip photonic devices with desired vector beams; however, this...

Graphene exhibit unique electronic properties and mechanical flexibility that are beneficial for next-generation electronics. Crumpling graphene on elastomer sheets can engineer the properties depending on wavelength and orientation while maintaining structural...

Continuous-wave (CW) lasing at room temperature is critical for integration with opto-electronic devices and optimal modulation of optical interactions. Plasmonic nanocavities integrated with gain can generate coherent light at sub-wavelength scales, while...

Selectively functionalized graphene can realize spatially defined properties that are highly desirable for atom-thin devices. We developed a scalable approach to realize area-specific properties in graphene using multiscale wrinkles. Patterned areas of graphene...

Metalenses are compact lensing components based on rationally designed nanoscale building blocks. These planar devices are crucial for miniaturized imaging systems that can be integrated into portable electronic and optical devices. However, existing metalenses have...

We achieved mechanical control of the lasing color by exploiting a lasing cavity based on periodic arrays of nanoparticles in a stretchable, polymer matrix. This materials system could achieve reversibly tunable lasing as well as superior sensitivity to applied...

Understanding the underlying mechanism for the synthesis of metallic nanoparticles is crucial for strategic creation of desirable particles. We have recently designed a correlative approach to detect, visualize, and characterize intermediate species during a seedless,...

Miniaturized lasers enable applications in on-chip optical communication, medical imaging, and nanoscale optical displays. Compared to traditional lasers, plasmonic nanolasers can break the diffraction limit and support ultrasmall mode volumes, but unwanted...

Plasmonic metasurfaces—structured materials with subwavelength units—are of interest for applications ranging from high resolution imaging to 3D holography. Integrated devices, however, are challenging to achieve because traditional plasmonic materials such as Ag or...

Patterning three-dimensional (3D) structure into two-dimensional (2D) graphene is important for applications in flexible electrodes, stretchable electronics and energy storage devices. We have demonstrated a conformal wrinkling process that can generate hierarchical...

Superhydrophobic surfaces that can also withstand mechanical deformation such as bending and stretching are important for applications such as robust self-cleaning, water-resistant electronics, and flexible microfluidics. We developed monolithic, multi-scale...

Surface plasmon polaritons (SPPs) are responsible for exotic optical phenomena including negative refraction, surface enhanced Raman scattering, and nanoscale focusing of light. Although many materials support SPPs, the choice of metal for most applications has been...

Plasmonic nanostructures concentrate optical fields into nanoscale volumes, which is useful for plasmonic nanolasers, surface enhanced Raman spectroscopy, and white-light generation. However, the short lifetimes of the emissive plasmons correspond to a rapid depletion...

Periodic metal nanoparticle (NP) arrays support narrow lattice plasmon resonances that can be tuned by changing the localized surface plasmons of the individual NPs in the array, NP periodicity, and dielectric environment. The high quality factors (100-200) of lattice...

Strain-induced wrinkling of a stiff skin on a soft base layer is emerging as a powerful bottom-up method to realize ordered and disordered patterns across an entire surface. We have developed a memory-based, sequential wrinkling process that can transform flat...

Plasmon lasers can support ultrasmall mode confinement and ultrafast dynamics with device feature sizes below the diffraction limit. However, most plasmon-based nanolasers rely on solid gain materials (inorganic semiconducting nanowire or organic dye in a solid...

Plasmonic nanoparticles (NPs) arranged into assemblies can manipulate near-field profiles and modify far-field characteristics compared to a single NP. The ability to tune each nanoparticle in a plasmonic assembly can reveal new architectures for plasmon-enhanced...

Apt-AuNS nanoconstructs composed of two primary components, an anisotropic gold nanostar (AuNS) core and a shell of secondary structure aptamer, AS1411, have shown great potential in cancer treatment. The high density of AS1411 that comprise the shell results in a...

Nanotexturing polymeric surfaces changes their surface properties while their bulk properties remain unchanged. Wrinkles and folds can increase the efficiency and mechanical stability of optical and electrical devices. We have found a parallel method to create...

Direct visualization of interactions between drug-loaded nanoparticles and the cancer cell nucleus is crucial for understanding the mechanism behind cancer cell death. Nanoconstructs composed of nucleolin-specific aptamers and gold nanostars were actively transported...

Solid-state photolithography (SSP) enables the capabilities of one of the most important tools in nano- and microfabrication, the mask aligner, to be performed on the benchtop. SSP can create patterns over a wide range of different length scales (down to several...

We are investigating the optical properties of 3D anisotropic plasmonic particles. Recently, we have designed a way to create nested Au pyramidal nanoshells. These particles exhibit two plasmon resonances at visible and near-infrared wavelengths that can be...

We are working on a new class of asymmetric metal particles: nanofabricated pyramids. Because their nanofabrication procedure is extremely versatile, pyramids are ideal for designing multifunctional plasmonic materials that have high potential for creating unexpected...

The interaction of light with surface plasmons — collective oscillations of free electrons — in metallic nanostructures leads to novel optical phenomena. These structures typically consist of ordered arrays of particles or holes with sizes of the order of 100 nm....

We have combined bottom-up chemical methods and top-down nanoscale patterning techniques—chemical nanofabrication—to generate patterned and free-standing transition metal chalcogenide (TMC) nanostructures. This approach is general and flexible and can produce (1)...

By combining near-field and far-field spectroscopy, we have provided direct evidence for the role of surface plasmons (SPs) in the enhanced optical transmission of light through metallic nanoscale hole arrays. Near-field optical images directly confirmed the presence...

Nanoscale fabrication methods provide a unique approach to synthesize nanoscale materials. We have used laser-assisted embossing to generate close-packed arrays of hemispherical nanowells with zeptoliter (zL)-volumes. Nanowells with diameters as small as 50 nm were...