Symposium EL12: Perspective on Applications of Metasurfaces—Advances in Metasurface Design, Fabrication, Integration and Material

Yueqiang Hu, Hunan University

Extreme Micro/Nanomanufacturing for Metasurface Applications

Written by Matthew Nakamura

In his talk, Yueqiang Hu, a professor at Hunan University, discusses advancements in micro/nanomanufacturing, utilized in the integrated-circuits industry and micro/nanosystems development with a focus on pushing manufacturing toward ultrasmall dimensions and ultrahigh precision for various applications. Hu introduces the processing capabilities available to Hunan University (HNU) like sketch and peel lithography, greyscale lithography, and conformal filling with ion beam polishing to achieve multiscale, multidimensional, and high-precision fabrication capabilities for functional micro/nanostructures. The presentation showcases applications in 2D and 3D metasurfaces as well as optical metadevices.

The second part of the talk delves into the realm of optical metasurfaces, emphasizing their advantages over traditional refractive optics. Metasurfaces, being ultrathin, multifunctional, and easily integrable through CMOS processes, are considered the next generation of optics. Hu explores the extreme fabrication requirements of dielectric metasurfaces, detailing the nanofabrication processes performed and highlights applications such as polarization modulation, vectorial color holography, multi-focal metalenses, 3D vectoral holography, and dispersion modulation. The presentation concludes by envisioning the future applications of these micro-nano fabrication processes in creating intelligent, compact, and multifunctional optical systems.

Symposium SF06: From Robotic Towards Autonomous Materials

Ugur Bozuyuk, Max Planck Institute for Intelligent Systems, Germany

Magnetic Surface Microrollers for Endovascular Navigation

Written by Birgul Akolpoglu

Ugur Bozuyuk’s talk on magnetic surface microrollers addressed current challenges in drug delivery and presented microrobotic solutions. Bozuyuk focuses on the role of targeting for efficient drug delivery applications, and highlights the potential of microrobotic drug delivery by external control mechanisms, such as magnetic fields. However, a limitation exists: the difficulty of microrobot locomotion in the bloodstream due to strong fluidic forces and other physiological challenges. To overcome this, Bozuyuk introduced magnetic surface microrollers propelled by rotating magnetic fields, demonstrating fast locomotion. While their potential for navigation in blood vessels was evident in microfluidic chips, he acknowledged the need to explore real-world limitations. Investigating microtopography effects, they found that surface roughness influenced motion, and they revealed further insights through computational fluid dynamics (CFD) simulations. The confinement effect, explored using cylindrical channels, showcased a fundamental barrier generated by the flow generated inside, causing the microrollers swim against the intended direction. Examining flow effects in different blood vessels, Bozuyuk observed variations in microroller performance. Microroller locomotion in big blood vessels is relatively easy due to the parabolic flow profile, however smaller vessels such as venules and capillaries have more flow velocities, preventing upstream locomotion. The talk concluded with a focus on biocompatibility, as they optimized new materials and conducted imaging-guided navigation experiments, showing potential in physiological environments. Bozuyuk's research contributes to advancing microrobotic capabilities for targeted drug delivery in complex biological systems.

Symposium EL10: Understanding the Inorganic-Organic Interface—The Case of Colloidal Nanoscale Materials

Inge Herrmann, ETH Zurich

Exploring Interplay of Engineered Materials with the Living by Label-Free Analytical Imaging

Written by Mruganka Parasnis

Nanoscale materials have been used in biomedicine due to specific drug delivery and antimicrobial activity. Inge Herrmann of ETH Zurich discussed how bioactive tissue glue with orchestrated bio response was created. Different phases of wound healing for blood vessels and remodeling were assessed, such as adhesive, antimicrobial, and angiogenic phases. The approach to do this is the versatile, reproducible scale combing inorganic materials such as cerium phosphate based nanozymes with documented properties with catalytic functions to convert them to inactive cerium phosphate. SEM and EDX show the adhesion of fibrin to tissue. The clotting time, rapid homogenesis, and cell survival rate was successful. Furthermore, it was administered in vivo to rats. The nano glue promoted healing, observed through an increase in the blood flow. Label-free detection of alterations in surrounding area of tissue was observed. Different architectures of nanoparticles showcased different bio responses. Proteomics was performed on the immune cell activator enrichment along with fluorescence microscopy to observe the localization of nanoparticles and chemical changes. After the analysis, the researchers concluded that the surgical sealants of polymers before leak happens can be used based on clinical symptoms in a chemically and mechanically demanding environment. A mutually interpenetrating network was fabricated which is a new adhesion technology for leak detection. The study can provide a mechanistic understanding of functional biomaterials and tissue response in in vitro and in vivo environments.

Symposium SB03: Molecular Biomimetics—Biology Meets Materials Science and Artificial Intelligence at the Molecular Dimensions

Xuliang Qian, Nanyang Technological University, Singapore

Harnessing Gradients for Self-Assembly of Peptide-Based Nanocapsules: A Pathway to Advanced Drug Delivery Systems

Written by Mruganka Parasnis

Xuliang Qian of Nanyang Technological University, Singapore, reported on the utilization of insect cuticle peptides for forming nanocapsules. Qian said that a one-step process was involved as a solvent exchange process. In this technique, the water and acetone were mixed together to form as a gradient interface for the localization and self-assembly of peptides to the nanocapsules. The self-assembly occurs due to intrinsic affinity and conformation of peptides to self-assemble at a particular concentration. This paves the way for the next-generation drug delivery of peptide nanocapsules.

Symposium EL07: 1D and 2D Materials—Electronic Properties and Device Applications

Farnaz Niroui, Massachusetts Institute of Technology

Van der Waals Integration beyond the Limits of Van der Waals Forces

Written by Corrisa Heyes

Farnaz Niroui of the Massachusetts Institute of Technology presents her work to expand the applications of van der Waals (vdW) integration as a physical stacking alternative to conventional heterostructure production by addressing the materials properties limitations of the method. She demonstrates an adhesive matrix transfer process where a hybrid transfer substrate is generated to leverage the higher adhesive capabilities of one material to support a layer transfer to a less adhesive desired material. This process further allows for single step 2D material-to-device fabrication with pristine interfaces, engineered functionalities, and alternate form factors (i.e., flexible substrates or arrays of devices) made without any solvents, polymers, or high temperature annealing processes. Additionally, Niroui points out that this process is not limited to 2D materials and shows how gold nanocubes can be assembled over a large area using this method.

Symposium EN08: Materials for Emerging Electrochemical Separations

Kiekede Boer, Wageningen University, Netherlands

Controlling Protein Ad- and Desorption by an Electrical Switch on Polymer-Coated Carbon Electrodes

Written by Ankita Mathur

Extracting useful substances from the waste-stream conserves resources and reduces pollution.

Kiekede Boer and co-workers work on extracting proteins from the waste stream using a very low cost capacitive deionization (CDI) technology. CDI is popular for ion selective water treatment technology, but these researchers have modified it for protein extraction from waste waters. Boer used oppositely charged polyelectrolyte coating over the porous carbon electrodes of the CDI to create a surface charge in the cell, even in the absence of an external electric field. This led to spontaneous adsorption of the negatively charged protein by the positively charged polyelectrolyte coated carbon electrode by electrostatic attraction. For the desorption, an external voltage of -1.2 V was applied to neutralize the positive charge and prevent re-absorption. The process was successful in generating 10 mg of β-lactoglobulin protein per gram of carbon electrode used. Boer is looking forward to extending this CDI technology by utilizing stimuli-responsive polymers in the porous carbon to improve selectivity and reversibility.

Symposium EL04: Materials and Devices for Neuromorphic Electronics and Bio-Interfaces

Quanwei Li, University of California, Berkeley

Probing Photosynthetic Light Harvesting with a Single Photon

Written by Md Afzalur Rab

Photosynthesis, using which primary producers generate foods to form the basis of an ecosystem,  plays a very important role to ensure the existence of lives on earth. But the actual mechanism how the photo energy is converted to chemical energy is yet to be well understood. Researchers have applied sophisticated spectroscopic techniques to understand the primary conversion dynamics of energy in the photosynthesis process.

In this talk, Quanwei Li from the University of California, Berkeley described their joint collaboration with Massachusetts Institute of Technology to develop an advanced photon-counting quantum light spectroscopic method to investigate light harvesting with only a single photon at a time. Since a single photon is the basic unit of light, understanding the energy transformation by the absorption of only a photon and successive emission can better help to probe the actual initial step of photosynthesis. Li and his group did an experiment on a collection of pigment-protein complexes from purple bacteria which appeared to be a ring, and measured the response to a laser pulse.

Their results indicate that the photosynthesis begins with a single-photon transition and proceeds with a single quantum of energy. It hints that we need to go beyond semi-classical spectroscopy to understand the mechanism. The research promises new insights at single-quantum level in analogy to single molecule experiments.

Symposium DS04: Accelerating Data-Driven Materials Research for Energy Applications

Ayush Narsaria, Shell Global

High-Throughput Screening and Experimental Validation of Aqueous Organic Redox Flow Battery Electrolytes

Written by Matthew Nakamura

Ayush Narsaria's talk highlighted the imperative need for advancing battery technologies to accommodate the growing share of renewables in the energy space. Aqueous organic redox flow batteries (AORFBs) emerged as a promising solution, boasting high ionic conductivity, safety, and cost-effectiveness. Narsaria introduced a groundbreaking computational workflow to screen millions of organic molecules, combining similarity metrics, machine learning predictions of redox potential and solubility, and considerations of availability and cost. This innovative approach successfully narrowed down the selection to approximately 60 molecules. Some of these molecules, already recognized for their high performance in AORFBs, were validated through cyclic voltammetry experiments. The talk underscores the critical role of computational methodologies in expediting the discovery of novel organic electroactive molecules, propelling advancements in redox flow battery applications for a sustainable energy future.

Symposium Joint Session: EN03/EN06/EN08.03

Written by Mruganka Parasnis

Anna Bressi, Sant’ Anna School of Advanced Studies, Italy

Investigating the Potential of Starch Bioplastic as a Precursor for Laser-Induced Graphene Synthesis: A Sustainable Approach

In the symposium cluster on energy and sustainable, researchers presented their studies on laser-induced graphene (LIG)—a three-dimensional porous material—which Anna Bressi of Sant’Anna School of Advanced Studies, Italy, describes “as a groundbreaking technology for the conversion of carbon-rich precursors into electrically conductive materials.” Bressi introduced work done on starch-based bioplastic precursors. She used starch from the highly available maize. The advantages of using starch as a precursor are that synthesis involves a single-step process, and does not involve wet lab processes or any other chemical compounds. The process is scalable and not expensive. It can be degraded in the soil easily after 12 days with no microbial growth. This paved a sustainable and efficient method for LIG, Bressi said.

Iuliia Steksova, Scuola Superiore Sant’Anna, Italy

Sustainable Composites from Almond and Hazelnut Shells for Green Laser-Induced Graphene

The high lignin content of almond and hazelnut shells, reported Iuliia Steksova of Scuola Superiore Sant’Anna, Italy, makes them suitable for the laser-induced graphene (LIG) process. These materials are low cost, low density, biodegradable, and nontoxic. The precursor is a conductive carbon structure. Chitosan was used as a matrix for enhanced mechanical and electrical properties. Steksova sees a possible future of scaling up this technique that would enable a one-step process toward the production of LIGs from low-cost materials in agricultural applications.

Rocío Hernández Leal, Tecnológico Nacional de México

Extraction and Characterization of Nanocellulose from Sources of Residual Biomass

Rocío Hernández Leal of Tecnológico Nacional de México discussed another area of green electronics: the nanocellulose extracted from agricultural biomass. Nanocellulose from cellulose has strength, flexibility, and high purity. It can be made by crushing fibers, bleaching, and acid hydrolysis. Usually, nanocellulose has a lot of applications in the pharmaceutical industry. Through various characterization techniques, Leal and co-workers were able to confirm agricultural biomass as a greener and sustainable industrial waste for the preparation of cellulose nanofibers.

Symposium EL08: Emerging Material Platforms and Fundamental Approaches for Plasmonics, Nanophotonics and Metasurfaces

Tony Heinz, Professor of Applied Physics and Photon Science at Stanford University

Properties and Control of Excitons in 2D Semiconductor Heterostructures

Written by Matthew Nakamura

Tony Heinz from Stanford University presented his group’s work on insights into excitons in 2D heterostructures, specifically in transition metal dichalcogenides. In these systems, stacked layers result in a type II band alignment, leading to interlayer excitons as the lowest-lying optical excited state. Notably, the static dipole moment of these charge-separated states allows for high tunability through external electric fields, offering a unique source with adjustable photon energy in visible and infrared spectra. Crystallographically aligned samples introduce distinctive exciton localization effects due to moiré potential. Heinz showcased recent progress in characterizing these states through optical absorption measurements and time-resolved, angle-resolved photoemission spectroscopy. The research sheds light on radiative lifetimes and the nature of exciton localization in moiré structures. Heinz emphasized the convergence of 2D materials and meta-optics, highlighting their complementary roles in providing precise control over materials excitations. The integration of these exciting fields holds significant potential for advancing optical research and a wide array of applications.