Ultrafast Metaphotonic PCR Chip with Near-Perfect Absorber.

Polymerase chain reaction (PCR) is the gold standard for nucleic acid amplification and quantification in diverse fields such as life sciences, global health, medicine, agricultural science, forensic science, and environmental science for global sustainability. However, implementing a cost-effective PCR remains challenging for rapid preventive medical action to the widespread pandemic diseases due to the absence of highly efficient and low-cost PCR chip-based POC molecular diagnostics. Here, this work reports an ultrafast metaphotonic PCR chip as a solution of a cost-effective and low-power-consumption POC device for the emerging global challenge of sustainable healthcare. This work designs a near-perfect photonic meta-absorber using ring-shaped titanium nitride to maximize the photothermal effect and realize rapid heating and cooling cycles during the PCR process. This work fabricates a large-area photonic meta-absorber on a 6-inch wafer cost-effectively using simple colloidal lithography. In addition, this work demonstrates 30 thermocycles from 65 (annealing temperature) to 95 °C (denaturation temperature) within 3 min 15 s, achieving an average 16.66 °C s-1 heating rate and 7.77 °C s-1 cooling rate during thermocycling, succeeding rapid metaphotonic PCR. This work believes a metaphotonic PCR chip can be used to create a low-cost, ultrafast molecular diagnostic chip with a meta-absorber.

Facile Fabrication of Titanium Nitride Nanoring Broad-Band Absorbers in the Visible to Near-Infrared by Shadow Sphere Lithography.

Plasmonic broad-band absorbers have received much attention because of their high absorption and potential applications for light-absorbing devices such as thermophotovoltaics, solar energy harvesting, and thermal emitters. However, the fabrication of complex structures in a large area and thermostability remains a great challenge. Here, we report a titanium nitride nanoring broad-band absorber that has over 95% average absorption in the visible and near-infrared regions (400-900 nm). Nanoring structures in a large area (inch2) are fabricated by shadow sphere lithography, which can innovatively increase fabrication efficiency. The nanoring absorber showed over 2.3 times higher-temperature increases than flat film under the irradiation of light. These large-scale and broad-band absorbers have potential applications for solar energy conversion devices such as thermophotovoltaics and photothermal devices.

Self-assembled pagoda-like nanostructure-induced vertically stacked split-ring resonators for polarization-sensitive dichroic responses.

Stacked split-ring resonators (SSRR) arrays exhibiting polarization-sensitive dichroic responses in both visible and near-infrared wavelengths are realized over a centimeter-scale large area. The SSRR arrays are derived from pagoda-like nanorods fabricated from the self-assembly of a lamellae-forming polystyrene-b-poly (methyl methacrylate) copolymer (PS-b-PMMA) confined in cylindrical pores of anodized aluminum oxide (AAO) template. Along the nanorod direction, PS and PMMA nanodomains were alternately stacked with the same distance. Silver crescents and semi-hemispherical covers, which are essential for SSRR with the polarization sensitivity, were obliquely deposited on the single side of the nanorod after removing the AAO template and reactive-ion etching treatment. These sophisticated nanoscale architectures made by bottom-up fabrication can be applied to structural color, optical anti-counterfeiting, and commercial optical components in a large area.

Multiple-patterning colloidal lithography-implemented scalable manufacturing of heat-tolerant titanium nitride broadband absorbers in the visible to near-infrared.

Broadband perfect absorbers have been intensively researched for decades because of their near-perfect absorption optical property that can be applied to diverse applications. Unfortunately, achieving large-scale and heat-tolerant absorbers has been remained challenging work because of costly and time-consuming lithography methods and thermolability of materials, respectively. Here, we demonstrate a thermally robust titanium nitride broadband absorber with >95% absorption efficiency in the visible and near-infrared region (400-900 nm). A relatively large-scale (2.5 cm × 2.5 cm) absorber device is fabricated by using a fabrication technique of multiple-patterning colloidal lithography. The optical properties of the absorber are still maintained even after heating at the temperatures >600 ∘C. Such a large-scale, heat-tolerant, and broadband near-perfect absorber will provide further useful applications in solar thermophotovoltaics, stealth, and absorption controlling in high-temperature conditions.

Dual Nanopatterns Consisting of Both Nanodots and Nanoholes on a Single Substrate.

Block copolymers (BCPs) with various nanostructures such as spheres, cylinders, gyroid, and lamellae, have received great attention for their application in nanolithography through nanopattern transfer to substrates. However, the fabrication of diverse geometries, shapes and sizes of nanostructure on a single substrate at the desired position could not be achieved because the nanostructure based on BCPs is mainly determined by the volume fraction of one block. Here, we synthesize polystyrene-hv-poly(methyl methacrylate) copolymer (PS-hv-PMMA), which contains a photocleavable linker at the junction point between PS and PMMA blocks. After vertically oriented PMMA cylindrical nanodomains in a thin film on a substrate were obtained, dual nanopatterns composed of high-density array of nanodots and nanoholes were successfully fabricated at the desired area on a single substrate using selective irradiation with a mask. The dual nanopatterns could be used to prepare metal (or metal oxide) nanostructure arrays consisting of both nanodots and nanoholes, which are utilized for smart sensors capable of simultaneously detecting two independent molecules on nanodots and nanoholes.