Abstract

TBA

Abstract

Liquid biopsy is a minimally invasive approach for cancer diagnosis using blood samples; however, detecting rare cancer-related cells among abundant background components remains challenging. To address this, we developed advanced microfluidic systems for highly sensitive single-cell analysis using parallelized microreactors. I present microreactor arrays integrating electrostatic trapping, transistor-based cell manipulation, surface modification, and electrochemical sensing. Using ferrocene-modified DNA aptamers targeting epithelial cell adhesion molecule (EpCAM), we achieved label-free electrochemical detection of membrane proteins on individual cancer cells. By immobilizing aptamer sensors in microwells comparable in size to single cells, the system enables scalable single-cell resolution analysis. Additionally, I introduce a two-dimensional flow cytometer (2DFC) based on a Single Photon Avalanche Diode (SPAD) array embedded in a microfluidic channel, allowing high-throughput and parallel fluorescence detection of target cells. The system successfully detects fluorescently labeled cancer cells in flow. These platforms enable sensitive and continuous detection of cancer biomarkers in blood, providing a promising approach for precise liquid biopsy and personalized medicine.

Abstract

Mass spectrometry has become an indispensable analytical tool for the detection and identification of small molecules across fields ranging from environmental monitoring to biomedical diagnostics. However, conventional matrix-assisted approaches often suffer from background interference in the low mass range, limiting their effectiveness for the analysis of small compounds. In this context, nanostructured materials have emerged as promising alternatives for surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). This presentation will highlight recent advances in the design of nanomaterial-based platforms for SALDI-MS detection. Particular emphasis will be placed on the role of nanostructured surfaces, such as porous silicon, graphene-derived materials, diamond and metal oxide nanostructures in promoting efficient laser energy absorption, analyte confinement and controlled ion generation. Beyond their intrinsic optical and thermal properties, the surface chemistry of these materials plays a critical role in modulating analyte adsorption and capture, wettability and local concentration effects. By combining nanostructured materials with tailored interfacial chemistries and micro/nanofabrication strategies, it becomes possible to develop highly sensitive analytical substrates compatible with miniaturized or lab-on-chip systems. Such approaches open new perspectives for rapid detection of small molecules in complex matrices and for the integration of mass spectrometry with emerging microanalytical technologies.

Abstract

TBA

Abstract

The transition to sustainable hydrogen production requires pathways that are not only low-carbon but also resource-efficient and economically viable. Here, we report a solar-driven mechano-electro-bioprocess that converts sewage sludge into carbon-negative hydrogen and value-added protein, providing a circular alternative to conventional water electrolysis. By replacing the energy-intensive oxygen evolution reaction (OER) with selective electroreforming of sludge-derived organics, the system significantly reduces energy demand while enhancing process safety.

Alkaline mechanochemical pretreatment enables near-complete solubilization of sludge-bound organics and immobilization of heavy metals, facilitating downstream electrochemical and biological processing. Using hierarchically porous Ni-based catalysts under photovoltaic powering, the system achieves high hydrogen production rates (13-14 L h^-1), ~10% solar-to-hydrogen efficiency, and >95% Faradaic efficiency, with OER contribution greatly suppressed. The resulting volatile fatty acid-rich stream is further upgraded by purple phototrophic bacteria into single-cell protein (SCP), achieving >63% carbon recovery.

Life-cycle and techno-economic analyses demonstrate carbon-negative performance and competitive hydrogen costs when co-products are valorized. This integrated platform establishes a scalable and modular approach for coupling wastewater treatment with renewable hydrogen generation, directly aligning with circular economy principles and future decentralized hydrogen infrastructures.

Abstract

NTT group has formulated a vision for zero environmental impact and declared its intention to achieve carbon neutrality by 2040. From that point of view, we are working on the development of artificial photosynthesis technology that combines NTT’s knowledge of semiconductors and electrochemistry. The artificial photosynthesis is a technique that uses sunlight to produce fuels from CO2 and water, and we expect this approach to be promising for CO2 recycling. We are conducting research and development aimed at improving the conversion efficiency from sunlight to hydrocarbons by developing a direct reduction system for gas phase CO₂ using gallium nitride (GaN)-based materials as the photoelectrode and gold fibers as the CO₂ reduction electrode. Furthermore, we are investigating the formation of a nickel oxide protective layer on GaN-based electrodes with the aim of suppressing GaN-based degradation, which is critical for improving device durability. In this presentation, we will discuss the progress made in improving conversion efficiency and durability through research on electrode structures, as well as outdoor experimental equipment designed for practical applications and the results of its evaluation.

Abstract

Neural electrodes are the core components of neuroelectronic devices, enabling the recording and stimulation of neural activity. Our research focuses on three primary areas: (1) the design and characterization of the neuron-electrode interface, (2) the influence of asymmetric microchannels on engineered neuronal circuits, and (3) the development of flexible neural interfaces for both in vivo and in vitro applications.

Microelectrode arrays (MEAs) link neurons and electronic systems, but current MEAs face challenges. To address these, we are developing nanomaterial-based MEAs, offering enhanced properties, leading to better cell-electrode coupling. Our hybrid structure combines vertical nanostraws and nanocavities (Fig. 1), enabling stable, non-invasive, long-term recording at sub-threshold resolution. [1]

Taylor et al. demonstrated that microfluidics is the most effective method of controlling axon guidance and connect with different neuronal populations. Combining them with microelectrode arrays (MEAs) allows to study how neurons function over time. Here we aim to characterize the impact of asymmetric microchannels on neuronal circuits in the lab and show how they affect activity profiles and the ratio of forward- vs. backward-propagating spikes.

Implantable neural prosthetic devices provide access to neural circuits and are important for brain-machine interfaces. We explore architectures, materials, and strategies for performance, aiming for acute and chronic in vivo applications. We use thin-film technology, surface micromachining, additive manufacturing, electrodeposition, kirigami, key-locking, and stacking with key-lock systems. These technologies support versatile applications ranging from epilepsy models and visual prosthetics to bidirectional communication along the visual pathway (Fig.2).[2,3].

Abstract

Understanding and controlling the dynamics of neural systems requires developing technologies that can record the signals used by neurons and control neural systems. However, current engineering technologies for this purpose have limitations in many factors, such as the lack of cell-specific stimulation for precise control, severe invasiveness and bio-incompatibility that are difficult to apply to actual medical treatment. Therefore, developing a new micro-interface system that is biocompatible while fully exerting multi-functionality and can precisely manipulate and monitor nerve activity is a major demand in the current biomedical and brain engineering fields. In this presentation, I would like to introduce a flexible and stretchable fiber-based probe for interfacing with neural systems. Various materials including polymer, hydrogel, carbon nanotube, and liquid metal will be incorporated with new manufacturing skill called thermal drawing process (TDP), which enables multifunctional fibers for multimodal neural investigation by optogenetic modulation, electrophysiological recording, and microfluidic delivery. Through this technology, I also intend to predict the appearance of future biomedical devices in neural fields such as ultra-long-term brain-machine interface. The technologies to be introduced in this presentation will not only contribute to human health and well-being by enabling natural interfacing between neural circuits and external machines/computers, but are also expected to contribute to the development of a future with hyper-connectivity.

Abstract

Understanding how neuronal networks function remains a key challenge in neuroscience. In vivo experiments provide valuable insights but are often limited by the complexity of brain tissue and the difficulty of isolating specific signals. In contrast, in vitro models offer a more controlled environment, allowing detailed investigation of neuronal activity at the cellular and network levels. However, current techniques still have important limitations. Fluorescent probes can induce phototoxic effects and are not well suited for long-term measurements, while conventional planar microelectrode arrays (MEAs) typically suffer from weak coupling with cells, leading to low signal amplitudes.

In this context, 3D nanoelectrode arrays (NEAs) have emerged as a promising approach to improve bioelectronic interfacing. By introducing vertical nanostructures and optimizing electrode materials at the nanoscale, it is possible to enhance the interaction with neuronal membranes and significantly improve signal quality. These devices enable stable, high-resolution recordings over long durations, at both the single-cell and network scales.

In this talk, I will present recent developments of NEA platforms, from device design to system-level integration, including their coupling with CMOS circuits for high-density recordings. I will also discuss applications to neuronal cultures, neurodegenerative models, and more complex systems such as brain organoids and human iPSC-derived neurons.

Abstract

Cancer immunotherapy has recently been successful in the treatment of various types of tumors. Cytotoxic lymphocytes, including cytotoxic T lymphocytes (CTLs), natural killer (NK) cells play an essential role in elimination of tumors by directly killing tumor cells. Therefore, evaluation of lymphocyte cytotoxicity against tumor cells is critical for the improvement of cancer immunotherapy. Lymphocyte cytotoxicity is a strictly regulated function requiring a multi-step “checkpoint” to minimize normal cell damage. First, cytotoxic lymphocytes migrate to tumor sites and make close contact with tumor cells (trafficking). Second, cytotoxic lymphocytes recognize distinct signatures of tumor cells and make stable contact with tumor cells (recognition). Third, cytotoxic lymphocytes exert cytotoxicity by exocytosis of lytic granules containing cytotoxic molecules, including perforin and granzyme B, to lysis tumor cells (execution). Lastly, cytotoxic lymphocytes successfully performed cytolysis of tumor cells detach from dead cells and re-engage tumor cells to perform further cytotoxicity (detach and re-engage). However, current cytotoxicity assays mostly provide information about final outcomes of cytotoxicity. To overcome this limitation, we are developing new assays that allow “stepwise” evaluation of lymphocyte cytotoxicity using dynamic imaging and microfabrication techniques.

Abstract

Neuromorphic computing (NC) aims to emulate the efficiency of the human brain by employing artificial synapses and neurons implemented with semiconductor devices, enabling energy-efficient large-scale data processing. Functional neural networks require both excitatory and inhibitory synapses. However, conventional CMOS-based implementations typically rely on a large number of transistors, capacitors, and resistors, resulting in increased circuit complexity, limited integration density, and higher energy consumption. Ferroelectric field-effect transistors (FeFETs) have recently emerged as promising candidates for neuromorphic applications due to their non-volatile polarization states and low operating energy. In this work, we demonstrate artificial synapses and neurons based on ambipolar ferroelectric Schottky barrier FETs (Fe-SBFETs). Owing to their ambipolar transport characteristics and ferroelectric polarization control, a single Fe-SBFET can function as either an excitatory or inhibitory synapse depending on the applied bias conditions. Furthermore, neuron-like behavior with thalamic functionality is realized using a compact circuit consisting of only five Fe-SBFETs. This device-level multifunctionality enables highly simplified neuromorphic circuit architectures while maintaining ultra-low energy consumption. The proposed approach provides a promising pathway toward scalable and energy-efficient neuromorphic systems based on ferroelectric semiconductor devices.

Abstract

This presentation explores the intersection of molecular electronics and bioelectrochemistry, focusing on the development of single-molecule devices for energy and biomedical applications. We discuss the fabrication of high-frequency molecular rectennas and advanced thermal management systems at the nanoscale. A central focus is placed on "activationless" electron transfer within nanoconfined redox-DNA systems, which behave as single-energy-level quantum dots at room temperature. By leveraging biomimetic principles, we demonstrate how these molecular architectures can mimic the efficient energetics of photosynthesis and redox proteins, offering tunable reorganization energy. The talk also introduces "QBIOL," a specialized software based on point stochastic processes designed to model quantum bioelectrochemical phenomena. Finally, we present the first experimental measurement of shot noise in a chemical reaction, revealing noise suppression that parallels solid-state quantum devices. These breakthroughs provide a framework for future ultra-sensitive eDNA sensors and integrated bio-hybrid systems, bridging the gap between fundamental quantum physics and scalable technological solutions for sustainability and global health.

Abstract

In recent years, microneedle-mediated transdermal drug delivery systems (DDSs) have emerged as promising alternatives to conventional hypodermic injection-based approaches, enabling painless, patient-friendly self-administration of biological therapeutics. Among these technologies, dissoluble microneedles have attracted considerable attention owing to their inherent safety and elimination of needle-associated risks.

We have developed novel fabrication strategies for biodegradable microneedle array patches (MAPs) that fundamentally differ from conventional processes such as stepwise casting. In this presentation, we introduce an advanced transdermal drug delivery platform based on dissoluble microneedle patches[1,2].

In parallel, we investigated a range of biosensor components to realize portable, point-of-care diagnostic devices that are disposable, user-friendly, low-cost, and highly sensitive. As part of this effort, we fabricated porous microneedles on paper substrates, establishing a unique platform for the direct integration of sensing elements. This device enables rapid and painless monitoring of interstitial skin fluid within seconds[3,4].

Furthermore, dissoluble MAPs have achieved commercial adoption over the past decade, driven by increasing interest in cosmetic and dermatological applications. We are currently collaborating with industrial partners to further enhance skin care efficacy, with a particular focus on the design of micro-sponge spicules that markedly increase skin permeability in a painless and intuitive manner.

Abstract

Recent advances in bio-MEMS and micro/nanofabrication technologies have enabled the development of platforms for understanding cellular and organ-level functions. We investigate bio-soft materials and microfabrication techniques to construct biomimetic microstructures that integrate living cells with engineered substrates. Our research aims to elucidate biological systems emerging from interactions among molecules, materials, and living organisms, and to construct novel intelligent soft materials and functional devices inspired by these insights that enable sensing, actuation, and dynamic cellular interactions in microdevices.

A key aspect of this work is the development of self-assembly processes using thin-film materials. By controlling interfacial mechanical stresses in layered structures such as graphene/parylene bilayers, three-dimensional rolled microstructures can be formed spontaneously. These structures enable the creation of brain-on-a-chip platforms in which neural aggregates are wrapped by flexible electrode arrays, allowing electrical activity from neural networks to be measured on chip. In addition, hydrogel-based microstructures fabricated through controlled buckling and delamination can form microfluidic channels and biomimetic actuators that reproduce biological motions similar to those of vascular or intestinal tissues.

These bio-soft material platforms provide a versatile approach for constructing organ- and tissue-mimetic microsystems. The integration of soft materials, microfabrication, and biosensing technologies is expected to contribute to next-generation biomedical devices and in-vitro models for drug discovery, disease modeling, and precision medicine.

Abstract

Signaling of biochemical and bioelectrical activities on biological interfaces plays a crucial role in acquiring precise and continuous physiological information. Recent progress in flexible and implantable medical electronics has enabled stable sensor attachment to complex internal tissues through mechanically adaptive designs. In this work, we present conformable organic electronic platforms designed for diverse bioapplications. The conformability of our devices is achieved through two approaches: ultra-thin structural design and the use of materials with intrinsically low Young’s modulus. Building upon this foundation for mapping bioelectrical signals in organs such as the brain and heart [1–3], we expand our platforms toward advanced biochemical sensing. Specifically, we utilized conformable substrates to fabricate microneedle arrays and implantable devices capable of continuously monitoring biochemical markers in interstitial fluids and sweat [4–6]. Furthermore, to achieve untethered and continuous operation in these sensing platforms, we integrated light-emitting diodes (LEDs) for optical information transduction [7], alongside distinctive circuit architectures for wireless power and data transmission, including inductive coupling [8] and self-powered systems [9]. This study highlights the potential of soft, bio-integrated platforms as a versatile foundation for next-generation implantable and wearable healthcare systems.

Abstract

We report directional heat conduction in isotopically purified graphite using Tesla valve architectures. Through phonon hydrodynamic transport, we achieved 15% asymmetric thermal conductivity between opposing directions at 45 K, exclusively within the 25–60 K hydrodynamic regime where phonons exhibit collective fluid-like behavior. This represents the first application of Tesla valve principles to thermal transport in crystalline solids. We fabricated 90 nm thick, 4.5 μm wide suspended graphite structures from isotopically enriched material (¹³C reduced to 0.02%), measured via microsecond time-domain thermoreflectance. Forward-flowing phonons traverse the main channel with minimal resistance, while reverse flow is diverted through bent channels, creating thermal impedance. Control experiments with silicon Tesla valves showed no rectification, confirming phonon hydrodynamics as essential. Our geometry-based approach promises advances in electronic thermal management.

Abstract

We present a recent conceptual frame and its implications regarding phonon coherence. Our theoretical proposition introduces a revised heat conduction formalism that incorporates both particle-like and wave-like behaviors of thermal phonons, integrating intrinsic and mutual coherence times into a new thermal conductivity expression [1]. This approach, validated through direct atomic simulations and theoretical arguments, is particularly relevant in complex crystals but also amorphous systems, where coherence effects dominate thermal transport.

We further examine the role of short-range spatial phonon coherence in resonant systems, revealing that this coherence length—largely independent of atomic interactions—can be tuned by adjusting resonance strength and frequency, thereby offering a robust method for engineering couplings between quasi-particles [2].

Additionally, the spatiotemporal coherence of lattice vibrations is shown to govern thermal conductivity across different phases of matter, diminishing from solid to liquid but increasing from liquid to gas, a behavior linked to atomic diffusion that provides a unified understanding of thermal transport [3].

Abstract

Materials capable of light upconversion—transforming low-energy photons into higher-energy ones—are pivotal in advancing optoelectronics, energy solutions, and photocatalysis. However, the discovery in various materials pays little attention to few-layer transition metal dichalcogenides, primarily due to their indirect bandgaps and weaker light-matter interactions. Here, we report pronounced upconversion photoluminescence (UPL) in few-layer transition-metal dichalcogenides. This joint theory-experiment study attributes the UPL to a resonant exciton-exciton annihilation process involving a pair of dark excitons with opposite momenta, followed by the spontaneous emission of upconverted bright excitons, which can achieve high upconversion efficiency. Additionally, the UPL is generic in MoS2, MoSe2, WS2, and WSe2, exhibiting high tunability from green to ultraviolet light. The findings pave the way for further exploration of light upconversion, including fundamental properties and device applications, in two-dimensional semiconductors.