NanoTechnology: Materials, Processes & Devices

Research that includes:

  • Development of nanostructure fabrication technology
  • Nanomagnetics, Microphotonics
  • CMOS Integrated Nanowires/Nanotubes (CMOS-Inn)

BPNX1037: Cellulose-Based Nanosensors for PFAS Detection

Jonghyun Shin
2025

The persistent use of per- and polyfluoroalkyl substances (PFAS) has resulted in their accumulation in ecosystems and biomagnification in humans, posing severe health risks, including kidney, breast, and testicular cancers, along with metabolic disruptions. However, the lack of platforms capable of simultaneous PFAS self-adsorption and self-detection has limited eco-friendly solutions, hindering effective PFAS management. Herein, we introduce an eco-friendly cellulose-based nanosensor platform capable of PFAS separation and monitoring through self-adsorption and self-sensing....

Lukasz Komza

Graduate Student Researcher
Physics
Professor Alp Sipahigil (Advisor)
Ph.D. 2026 (Anticipated)

Lukasz Komza is a Physics PhD student at the University of California, Berkeley. He started working with Alp Sipahigil in the Quantum Devices Group in 2021 on the characterization and integration of silicon qubits in photonics. Prior to starting his PhD, Lukasz interned at Bell Labs in Murray Hill, NJ, working with Michael Eggleston on optical coherence tomography. He studied quantum light sources in 2D materials with Stefan Strauf during his undergraduate education, where he received the Alfred M. Mayer prize.

Synergistic Effects of Pd Single Atoms and Nanoclusters Boosting SnO2 Gas Sensing Performance

Yaprak Ozbakir
Yong Xia
Aifei Pan
Jiyun Hong
Jorge E. Perez-Aguilar
Simon R. Bare
Francesca Rossi
Rohan Dhall
Afnan Ali Alghannam
Nishit Goel
Stephen Bart
Carlo Carraro
Roya Maboudian
2025

Tin (IV) oxide-supported Pd is a promising heterogenous catalyst for CO oxidation relevant for environmental cleanup reactions. In this study, atomically dispersed catalyst Pd on SnO2 (ADC Pd/SnO2) hybrid material is successfully synthesized via a straightforward wet chemistry method and is found to exhibit superior performance toward CO sensing. Ex-situ EXAFS analysis confirms the formation of single Pd atoms and small Pd nanoclusters stabilized on the SnO2(110) surface. The material exhibits high efficiency in generating adsorbed O2– as well as high activity in catalyzing CO oxidation at...

Subtractive Microfluidics in CMOS

Wei-Yang Weng
Alexander Di
Xiang Zhang
Ya-Chen (Justine) Tsai
Yan-Ting Hsiao
Jun-Chau Chien
2024

This paper introduces a microfluidics platform embedded within a silicon chip implemented in CMOS technology. The platform utilizes a one-step wet etching method to create fluidic channels by selectively removing CMOS back-end-of-line (BEOL) routing metals. We term our technique “subtractive” microfluidics, to complement those fabricated with additive manufacturing. Three types of structures are presented in a TSMC I80-nm CMOS chip: (1) passive microfluidics in the form of a micro-mixer and a 1: 64 splitter, (2) fluidic channels with embedded ion-sensitive field-effect transistors (ISFETs...

BPNX1006: Quantitative Optical Characterization of Indium Selenide

Jamie Geng
2024

Bulk gamma-InSe has a direct bandgap of 1.24 eV, which corresponds to near infrared (NIR) wavelengths (λ = 1.0 µm) useful in optoelectronic applications from biometric detectors to silicon photonics. However, its potential for optoelectronic applications is largely untapped due in part to the lack of quantitative studies of its optical properties. Here, we study the unusually low absorptance and high photoluminescence quantum efficiency of single-crystalline InSe flakes with thickness in the hundreds of nanometers. InSe emits brightly at room temperature from its direct bandgap with a peak...

Hyong Min Kim

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2028 (Anticipated)

Hyong is a Ph.D. student in the Electrical Engineering and Computer Sciences Department at University of California, Berkeley. He received his Bachelor's Degree in Electrical Engineering from the Univeristy of Pennsylvania in 2023. In his undergraduate research, Hyong studied quantum emission from strained 2D materials, ferroelectric field-emission transistors based on AlScN/2D material heterostructures, and scanning probe characterization of 1D-2D material interfaces. Hyong's current research at Berkeley is on fabricating next-generation Mid-Wave Infrared (MWIR) optoelectronic devices...

Dehui Zhang

Postdoctoral Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)

Dehui Zhang is a postdoctoral researcher in Electrical Electrical Engineering and Computer Sciences at the University of California, Berkeley, a postdoctoral researcher at Berkeley Sensor & Actuator Center (BSAC), and a research affiliate in the Materials Science Division at Lawrence Berkeley National Laboratory. He received a Ph.D. in Electrical and Computer Engineering from University of Michigan, Ann Arbor in 2021, and was a postdoctoral researcher at University of California, Los Angeles in 2021-2023. Dehui Zhang joined Javey Research Group in September 2023...

BPNX1003: Copolymer-Template Fabrication of Metal Oxides with Tailored Porosity toward High-performance Gas Sensors

YoungJun Kim
HyoJun Min
Tzu-Chiao Wei
Yaprak Ozbakir
Carlo Carraro
2025

Metal oxide semiconductors (MOX) such as SnO2 are widely used in chemiresistive gas sensors due to their high chemical and thermal stability, low cost, and tunable chemical and electronic properties. The introduction of porosity to the MOX structure enhances their gas-sensing properties by increasing the surface area available for interactions with gas molecules. This higher surface area enhances the sensor's sensitivity by providing more active sites for gas adsorption. Also, a faster response/recovery time can be obtained as gas molecules can more quickly interact with a...

BPNX1002: Atomically Dispersed Metals on Graphene Oxide for High-Performance Electrochemical Biosensors

Yaprak Ozbakir
HyoJun Min
2025

Atomically dispersed metal catalysts have garnered considerable attention due to their unique properties and superior catalytic activity. The isolation of metal atoms on the matrix offers enhanced catalytic performance even with a small content of noble metal loading. This class of materials provides exciting opportunities to improve the performance of chemical and biochemical sensors. In this work, we have selected Pd as the catalysts because of its high catalytic activity and graphene oxide as the matrix because of its high electrical conductivity and unique electrochemical properties....

BPNX1001: Enhancing the Humidity Resistance of Chemiresistive Gas Sensors through Surface Functionalization

Tzu Chiao Wei
Yaprak Ozbakir
HyoJun Min
2025

Chemiresistive gas sensors based on semiconductor metal oxides, such as tin dioxide, help to identify and monitor toxic gases and pollution, and play a vital role in industrial and environmental applications. However, the interfering effect of ambient humidity is a major challenge in their reliable operation, as water molecules on the oxide surface can affect the sensitivity and other characteristics of the sensor. To address this challenge, we are modifying the sensor surface by applying thin hydrophobic layers, such as hexamethyldisilazane (HMDS), to achieve ultrahydrophobicity,...