This PDF file contains the front matter associated with SPIE Proceedings Volume 13126, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

We study unique optical trapping phenomenon at glass/solution interface for gold nanoparticles with the diameter of 200 ~ 400 nm. With prolonged irradiation, gathering of many NPs forms a dynamically moving and fluctuating assembly like a flying group of birds in sky. We call this phenomenon as optical trapping and swarming, which extends to a few ten µm, much larger than the focal area of the 1064 nm trapping laser. We have elucidated the swarming dynamics and mechanism in view of optical binding and its expanded network, while here we design new experiments of the swarming toward a plasmonic machine, depending on laser polarization. The morphology and size of the Au NP swarming is intrinsically determined by optical, physical, and chemical parameters of NP, which is demonstrated by utilizing silica-coated gold nanoparticles. Further the swarming can be controlled by performing trapping and swarming on patterned glasses; one is on gold nanodisk pattern fabricated lithographically and the other is on polycaprolactone microchannel prepared by electrospinning writing method. The dumbbell-shaped morphology is switched from bidirectional to unidirectional, and its shape is modified. The dynamically fluctuating Au NPs can induce hydrodynamic flow in solution and give mechanical pressure to the surrounding. Also, the swarming NPs are heated by photo-absorption of the 1064 nm laser. The present findings indicates that the swarming gold nanoparticles can work as a plasmonic machine, and its systematic study will enable various designs of dynamic matter in the few ten micrometer domain.

This work underscores the advancements in Surface-enhanced Raman scattering (SERS) technology, particularly in biomedicine. Known for its high sensitivity and resolution, SERS is a powerful tool for detecting low-concentration analytes. The study focuses on SERS-based nanosensors applied to imaging, biochemical monitoring, diagnostics, and therapy. By combining Raman spectroscopy with SERS, the research achieves precise HER2 quantification in breast cancer cells at the single-cell level, offering insights into cancer heterogeneity and supporting personalized treatments. Additionally, SERS is used to monitor Galunisertib delivery within living colorectal cancer cells, using diatomite-based nanovectors with gold nanoparticles and a pH-sensitive gelatin coating. This setup allows for controlled drug release in response to the tumor microenvironment, with real-time, label-free quantification of Galunisertib at very low concentrations. These findings highlight the potential of SERS to improve the precision and effectiveness of drug delivery and cancer treatment strategies.

Neurons form complex networks and communicate through synaptic connections. The molecular dynamics of cell surface molecules at synaptic terminals are essential for elucidating synaptic transmission and plasticity in biological neural networks. To achieve artificial control of synaptic transmission in neural networks at the single-synapse level, we propose and demonstrate the application of optical trapping for laser-induced perturbation to cellular molecules on neurons. In this study, we investigated the effects of optical forces on the dynamics of cell molecules in an optical trap on neurons. The diffusion properties of the cell surface molecules under optical trapping were evaluated using fluorescence analysis with single-particle tracking and fluorescence correlation spectroscopy. Molecular diffusion at the cell surface of neurons was compared to that of lipid molecules in artificial bilayers. Moreover, the molecular dynamics in an optical trap without fluorescent labeling under live cell conditions was evaluated using Raman spectroscopy.

Nonlinear optical phenomena play important roles in the vast emerging fields of micro- and nanotechnology. This paper describes the general characteristics of nonlinear optical materials and systems, with a focus on parametric amplification, frequency-doubling with pump depletion, quantum noise accompanying attenuation and amplification of light beams, and parametric fluorescence.

In recent years, micro- and nanofluidic channels for single nanoparticle analysis have attracted much attention. However, it is difficult to control the transport velocity of target particles introduced into the sensing part because of thermal fluctuations in liquids. In this study, we have developed a novel technique for controlling microfluidic flows to precisely induct single nanoparticles into micro- and nanofluidic channels. Herein, we fabricate a nanofluidic channel with a width of about 500 nm on a quartz-glass surface that crosses a pair of parallel microfluidic channels printed on a PDMS surface. Nanoparticles dispersed in an electrolyte solution on one side of the microchannel are inducted along the microchannel and into the nanochannel by flow control of the other microchannel. The nanoparticles gradually migrate toward a nanochannel opening, driven by the drag force and electrostatic force and experiencing thermal fluctuations. Transport of these nanoparticles is recorded using a high-speed CMOS camera, and the trajectories are analyzed by sing particle tracking technique. As a result, the target nanoparticles are effectively attracted to the nanochannel opening with appropriate transport velocity overcoming thermal fluctuations. Furthermore, the nanoparticle detection frequency is improved by the voltage and pressure differences between the microchannels. The present method is expected to contribute to the optical manipulation technology of single nanoparticles in liquids in micro- and nanofluidic channels.

Photomechanical materials are the missing link in all-optical device technologies that require the integration of logic, actuation, sensing and information transmission. In this work, we assess the photomechanical/rheological response of a novel material based on a liquid crystal network. We use these results to determine the material’s figure of merit, which describes the photomechanical efficiency, and compare the results with other representative materials. We also discuss potential mechanisms based on the time evolution of the photomechanical response, and how their contributions affect the total response. The large nonlinearity in these materials is unique and may given them an advantage over existing materials.

The semiconductor industry's growing demand for advanced packaging in smaller devices has led to the adoption of high-aspect ratio Cu pins as an alternative to conventional solder bumps. This approach allows for higher density and increased terminals in applications like mobile phones and wearables. A novel mounting method for these pins involves repeated dropping onto the package surface using a specially designed 3D mask stencil, as traditional pick-and-place methods prove challenging due to the pins' aspect ratio. The efficiency of this process is evaluated through statistical analysis and simulation. A mounting simulation model is developed, incorporating pre-defined design parameters of the 3D mask at various levels. The response surface method is used to assess the impact of each design parameter on mounting efficiency and determine the optimal 3D mask design. The design of experiments considers three parameters (counter bore diameter, depth, and hole diameter) at three levels, with simulations repeated five times under each condition. Analysis results indicate that the hole diameter in the 3D mask is the most significant factor influencing mounting efficiency. To validate these findings, an experimental setup compares the number of mounted pins for each 3D mask design. The study concludes that optimizing the hole diameter, a crucial design parameter in the 3D mask, can substantially improve mounting efficiency in this innovative packaging approach.

Currently, there are various techniques for clinical diagnosis of infections. During the last pandemic caused by Sars-CoV-2, the importance and need for rapid, economical and accessible diagnostic systems became evident. Demonstrating that they are fundamental tools in the prevention and control of diseases. Thus, Point-of-Care (PoC) devices emerge as an alternative with the potential to improve access to the diagnosis of infectious diseases. These are devices that allow immediate diagnosis in low-complexity centers, reducing costs, streamlining the analysis, and, above all, considerably increasing the confidence intervals of the diagnoses. Many of the most used clinical diagnostic techniques base their determination on optical techniques, mostly colorimetric and fluorescent. These types of determinations are gaining wide attention as non-destructive tools, visible to the human eye, and capable of providing real-time and in-situ responses. The present work seeks to provide alternatives for better PoC diagnostic systems. We will focus on colorimetric determinations, widely used in nucleic acid amplification tests. However, they have the disadvantage of depending, in certain cases, on the subjectivity of the person analyzing the sample (visual diagnosis). Following this, a portable colorimetric device was developed, capable of objectively discretizing between positive and negative tests. Specifically, by performing spectral analysis of each sample and evaluating its absorbance in the visible spectrum.