Electrical programmable multilevel nonvolatile photonic random-access memory.

Photonic Random-Access Memories (P-RAM) are an essential component for the on-chip non-von Neumann photonic computing by eliminating optoelectronic conversion losses in data links. Emerging Phase-Change Materials (PCMs) have been showed multilevel memory capability, but demonstrations still yield relatively high optical loss and require cumbersome WRITE-ERASE approaches increasing power consumption and system package challenges. Here we demonstrate a multistate electrically programmed low-loss nonvolatile photonic memory based on a broadband transparent phase-change material (Ge2Sb2Se5, GSSe) with ultralow absorption in the amorphous state.

Interstitial Photothermal Therapy Generates Durable Treatment Responses in Neuroblastoma.

Photothermal therapy (PTT) represents a promising modality for tumor control typically using infrared light-responsive nanoparticles illuminated by a wavelength-matched external laser. However, due to the constraints of light penetration, PTT is generally restricted to superficially accessible tumors. With the goal of extending the benefits of PTT to all tumor settings, interstitial PTT (I-PTT) is evaluated by the photothermal activation of intratumorally administered Prussian blue nanoparticles with a laser fiber positioned interstitially within the tumor.

Programmable chalcogenide-based all-optical deep neural networks.

We demonstrate a passive all-chalcogenide all-optical perceptron scheme. The network's nonlinear activation function (NLAF) relies on the nonlinear response of GeSbTe to femtosecond laser pulses. We measured the sub-picosecond time-resolved optical constants of GeSbTe at a wavelength of 1500 nm and used them to design a high-speed GeSbTe-tuned microring resonator all-optical NLAF.

100 GHz micrometer-compact broadband monolithic ITO Mach-Zehnder interferometer modulator enabling 3500 times higher packing density.

Electro-optic modulators provide a key function in optical transceivers and increasingly in photonic programmable application-specific integrated circuits (ASICs) for machine learning and signal processing. However, both foundry-ready silicon-based modulators and conventional material-based devices utilizing lithium-niobate fall short in simultaneously providing high chip packaging density and fast speed. Current-driven ITO-based modulators have the potential to achieve both enabled by efficient light-matter interactions.

Integrated ultra-high-performance graphene optical modulator.

With the increasing need for large volumes of data processing, transport, and storage, optimizing the trade-off between high-speed and energy consumption in today's optoelectronic devices is getting increasingly difficult. Heterogeneous material integration into silicon- and nitride-based photonics has showed high-speed promise, albeit at the expense of millimeter-to centimeter-scale footprints. The hunt for an electro-optic modulator that combines high speed, energy efficiency, and compactness to support high component density on-chip continues.

Mimicking Native Heart Tissue Physiology and Pathology in Silk Fibroin Constructs through a Perfusion-Based Dynamic Mechanical Stimulation Microdevice.

In vitro cardiomyocyte (CM) maturation is an imperative step to replicate native heart tissue-like structures as cardiac tissue grafts or as drug screening platforms. CMs are known to interpret biophysical cues such as stiffness, topography, external mechanical stimulation or dynamic perfusion load through mechanotransduction and change their behavior, organization, and maturation. In this regard, a silk-based cardiac tissue (CT) coupled with a dynamic perfusion-based mechanical stimulation platform (DMM) for achieving maturation and functionality in vitro is tried to be delivered.

Quantifying Information via Shannon Entropy in Spatially Structured Optical Beams.

While information is ubiquitously generated, shared, and analyzed in a modern-day life, there is still some controversy around the ways to assess the amount and quality of information inside a noisy optical channel. A number of theoretical approaches based on, e.g.

Symmetry perception with spiking neural networks.

Mirror symmetry is an abundant feature in both nature and technology. Its successful detection is critical for perception procedures based on visual stimuli and requires organizational processes. Neuromorphic computing, utilizing brain-mimicked networks, could be a technology-solution providing such perceptual organization functionality, and furthermore has made tremendous advances in computing efficiency by applying a spiking model of information.

Heterogeneously integrated ITO plasmonic Mach-Zehnder interferometric modulator on SOI.

Densely integrated active photonics is key for next generation on-chip networks for addressing both footprint and energy budget concerns. However, the weak light-matter interaction in traditional active Silicon optoelectronics mandates rather sizable device lengths. The ideal active material choice should avail high index modulation while being easily integrated into Silicon photonics platforms.

Exploiting Unique Alignment of Cobalt Ferrite Nanoparticles, Mild Hyperthermia, and Controlled Intrinsic Cobalt Toxicity for Cancer Therapy.

Nanoparticle-based magnetic hyperthermia is a well-known thermal therapy platform studied to treat solid tumors, but its use for monotherapy is limited due to incomplete tumor eradication at hyperthermia temperature (45 °C). It is often combined with chemotherapy for obtaining a more effective therapeutic outcome. Cubic-shaped cobalt ferrite nanoparticles (Co-Fe NCs) serve as magnetic hyperthermia agents and as a cytotoxic agent due to the known cobalt ion toxicity, allowing the achievement of both heat and cytotoxic effects from a single platform.

Biodegradable and Insoluble Cellulose Photonic Crystals and Metasurfaces.

The replacement of plastic with eco-friendly and biodegradable materials is one of the most stringent environmental challenges. In this respect, cellulose stands out as a biodegradable polymer. However, a significant challenge is to obtain biodegradable materials for high-end photonics that are robust in humid environments.

CLEAR: A Holistic Figure-of-Merit for Post- and Predicting Electronic and Photonic-based Compute-system Evolution.

Continuing demands for increased computing efficiency and communication bandwidth have pushed the current semiconductor technology to its limit. This led to novel technologies with the potential to outperform conventional electronic solutions such as photonic pre-processors or accelerators, electronic-photonic hybrid circuits, and neural networks. However, the efforts made to describe and predict the performance evolution of compute-performance fall short to accurately predict and thereby explain the actually observed development pace with time; that is all proposed metrics eventually deviate from their development trajectory after several years from when they were originally proposed.

Nanoparticle-Based Hybrid Scaffolds for Deciphering the Role of Multimodal Cues in Cardiac Tissue Engineering.

Myocardial microenvironment plays a decisive role in guiding the function and fate of cardiomyocytes, and engineering this extracellular niche holds great promise for cardiac tissue regeneration. Platforms utilizing hybrid hydrogels containing various types of conductive nanoparticles have been a critical tool for constructing engineered cardiac tissues with outstanding mechanical integrity and improved electrophysiological properties. However, there has been no attempt to directly compare the efficacy of these hybrid hydrogels and decipher the mechanisms behind how these platforms differentially regulate cardiomyocyte behavior.

Towards integrated metatronics: a holistic approach on precise optical and electrical properties of Indium Tin Oxide.

The class of transparent conductive oxides includes the material indium tin oxide (ITO) and has become a widely used material of modern every-day life such as in touch screens of smart phones and watches, but also used as an optically transparent low electrically-resistive contract in the photovoltaics industry. More recently ITO has shown epsilon-near-zero (ENZ) behavior in the telecommunication frequency band enabling both strong index modulation and other optically-exotic applications such as metatronics. However, the ability to precisely obtain targeted electrical and optical material properties in ITO is still challenging due to complex intrinsic effects in ITO and as such no integrated metatronic platform has been demonstrated to-date.

Planar Aperiodic Arrays as Metasurfaces for Optical Near-Field Patterning.

Plasmonic metasurfaces have spawned the field of flat optics using nanostructured planar metallic or dielectric surfaces that can replace bulky optical elements and enhance the capabilities of traditional far-field optics. Furthermore, the potential of flat optics can go far beyond far-field modulation and can be exploited for functionality in the near-field itself. Here, we design metasurfaces based on aperiodic arrays of plasmonic Au nanostructures for tailoring the optical near-field in the visible and near-infrared spectral range.

Giant-Shell CdSe/CdS Nanocrystals: Exciton Coupling to Shell Phonons Investigated by Resonant Raman Spectroscopy.

The interaction between excitons and phonons in semiconductor nanocrystals plays a crucial role in the exciton energy spectrum and dynamics, and thus in their optical properties. We investigate the exciton-phonon coupling in giant-shell CdSe/CdS core-shell nanocrystals via resonant Raman spectroscopy. The Huang-Rhys parameter is evaluated by the intensity ratio of the longitudinal-optical (LO) phonon of CdS with its first multiscattering (2LO) replica.

Effects of graphene defects on gas sensing properties towards NO detection.

The crystal structure of graphene flakes is expected to significantly affect their sensing properties. Here we report an experimental investigation on the crystalline structure of graphene aimed at exploring the effects on the gas sensing properties. The morphology of graphene, prepared via Chemical Vapor Deposition (CVD), Liquid Phase Exfoliation (LPE) and Mechanical Exfoliation (ME), is inspected through Raman spectroscopy, Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM).

Biomechanical Strain Exacerbates Inflammation on a Progeria-on-a-Chip Model.

Organ-on-a-chip platforms seek to recapitulate the complex microenvironment of human organs using miniaturized microfluidic devices. Besides modeling healthy organs, these devices have been used to model diseases, yielding new insights into pathophysiology. Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disease showing accelerated vascular aging, leading to the death of patients due to cardiovascular diseases.

Confined Acoustic Phonons in Colloidal Nanorod Heterostructures Investigated by Nonresonant Raman Spectroscopy and Finite Elements Simulations.

Lattice vibrational modes in cadmium chalcogenide nanocrystals (NCs) have a strong impact on the carrier dynamics of excitons in such confined systems and on the optical properties of these nanomaterials. A prominent material for light emitting applications are CdSe/CdS core-shell dot-in-rods. Here we present a detailed investigation of the acoustic phonon modes in such dot-in-rods by nonresonant Raman spectroscopy with laser excitation energy lower than their bandgap.

Aligned carbon nanotube-based flexible gel substrates for engineering bio-hybrid tissue actuators.

Muscle-based biohybrid actuators have generated significant interest as the future of biorobotics but so far they move without having much control over their actuation behavior. Integration of microelectrodes into the backbone of these systems may enable guidance during their motion and allow precise control over these actuators with specific activation patterns. Here, we addressed this challenge by developing aligned CNT forest microelectrode arrays and incorporated them into scaffolds for stimulating the cells.

A liver-on-a-chip platform with bioprinted hepatic spheroids.

The inadequacy of animal models in correctly predicting drug and biothreat agent toxicity in humans has resulted in a pressing need for in vitro models that can recreate the in vivo scenario. One of the most important organs in the assessment of drug toxicity is liver. Here, we report the development of a liver-on-a-chip platform for long-term culture of three-dimensional (3D) human HepG2/C3A spheroids for drug toxicity assessment.

Highly Elastic and Conductive Human-Based Protein Hybrid Hydrogels.

A highly elastic hybrid hydrogel of methacryloyl-substituted recombinant human tropoelastin (MeTro) and graphene oxide (GO) nanoparticles are developed. The synergistic effect of these two materials significantly enhances both ultimate strain (250%), reversible rotation (9700°), and the fracture energy (38.8 ± 0.

Analysis of MWCNT/epoxy composites at microwave frequency: reproducibility investigation.

A wide-band microwave characterization of nanocomposites based on commercial multiwalled carbon nanotubes (MWCNTs) and epoxy resin is presented. The sample preparation method is discussed in detail. Field emission scanning electron microscopy is used for morphological sample analysis of nanocomposites and MWCNTs.