Ali Javey (Advisor)

Research Advised by Professor Ali Javey

Javey Group:  List of Projects | List of Researchers

BPN932: A Fully Integrated and Self-Powered Smartwatch for Continuous Sweat Glucose Monitoring

Jiangqi Zhao
Yuanjing Lin
2019

Wearable devices for health monitoring and fitness management have foreseen a rapidly expanding market, especially those for noninvasive and continuous measurements with real-time display that provide practical convenience and eliminated safety/infection risks. Herein, a self- powered and fully integrated smartwatch that consists of flexible photovoltaic cells and rechargeable batteries in form of a “watch strap”, electrochemical glucose sensors, customized circuits and display units integrated into a “dial” platform, is...

BPN921: Passivating Contacts for Silicon Solar Cells by Lewis Acids and Bases

Wenbo Ji
2020

A salient characteristic of solar cells is their ability to subject photo-generated electrons and holes to pathways of asymmetrical conductivity - assisting them toward their respective contacts. All commercially available crystalline silicon (c-Si) solar cells achieve this by making use of doping in either near-surface regions or overlying silicon-based films. Despite being commonplace, this approach is hindered by several optoelectronic losses and technological limitations specific to doped silicon. Our previous work on low/high work function dopant-free...

BPN896: Drug Monitoring with Wearable Sweat Sensors

Li-Chia Tai
2020

Drug monitoring plays crucial roles in doping control and precision medicine. It helps physicians tailor drug dosage for optimal benefits, track patients’ compliance to prescriptions and understand the complex pharmacokinetics of drugs. Conventional drug tests rely on invasive blood draws. While urine and sweat are attractive alternative biofluids, the state-of-the-art methods require separate sample collection and processing steps and fail to provide real-time information. Here we present a wearable platform for drug monitoring. Both stationary iontophoretic induction...

BPN888: Large-Area Processing of Monolayer Semiconductors for Lighting Applications

Der-Hsien Lien
2020

Transition-metal dichalcogenide monolayers have naturally terminated surfaces and can exhibit a near-unity photoluminescence quantum yield in the presence of suitable defect passivation. To date, steady-state monolayer light-emitting devices suffer from Schottky contacts or require complex heterostructures. We demonstrate a transient-mode electroluminescent device based on transition-metal dichalcogenide monolayers (MoS2, WS2, MoSe2, and WSe2) to overcome these problems. Electroluminescence from this dopant-free two- terminal device is obtained by...

BPN944: Wearable Sweat Sensors for Nutrients Monitoring

Hnin Yin Yin Nyein
Jiangqi Zhao
2020

Nutrients are essential parts of our lives for normal growth and development of body functions. An average person’s intake of nutrients per day is not enough to sustain body needs and thrive the development. To achieve optimal nutrient balance for development, especially in children, it is important to keep track of nutrients level in our body. Sweat, which contains many chemicals including vitamins and amino acids, is an attractive biofluid for routine non- invasive assessment of nutrients level. In this work, we developed a wearable sensor that can accurately provide...

BPN929: Electrochemical Sensors with Reduced Drift and Enhanced Stability

Yuanjing Lin
2020

Development of reliable glucose sensors for noninvasive monitoring without interruption or limiting users’ mobility is highly desirable, especially for diabetes diagnostic which requires routine/long term monitoring. However, their applications are largely limited by the relatively poor stability. Herein, a porous membrane is synthesized for effective enzymes immobilization and it is robustly anchored to the modified nanotextured electrode solid contacts, so as to realize glucose sensors with significantly enhanced sensing stability and mechanical robustness....

Materials Science and Device Physics of 2-Dimensional Semiconductors

Hui Fang
Ali Javey
Ramamoorthy Ramesh
Junqiao Wu
Eli Yablonovitch
2014

Materials and device innovations are the keys to future technology revolution. For MOSFET scaling in particular, semiconductors with ultra-thin thickness on insulator platform is currently of great interest, due to the potential of integrating excellent channel materials with the industrially mature Si processing. Meanwhile, ultra-thin thickness also induces strong quantum confinement which in turn affect most of the material properties of these 2-dimensional (2-D) semiconductors, providing...

Micro-Columnated Loop Heat Pipe: The Future of Electronic Substrates

Navdeep Singh Dhillon
Albert P. Pisano
Liwei Lin
Omer Savas ̧
Ali Javey
2012
The modern world is run by semiconductor-based electronic systems. Due to continuous improvements in semiconductor device fabrication, there is a clear trend in the market towards the development of electronic devices and components that not only deliver enhanced computing power, but are also more compact. Thermal management has emerged as the primary challenge in this scenario where heat flux dissipation of electronic chips is increasing exponentially, but conventional cooling solutions such as conduction and...

Micro Chemical Vapor Deposition for the Synthesis of Nanomaterials

Qin Zhou
Liwei Lin
Albert P. Pisano
Ali Javey
2011

MEMS (Microelectromechanical Systems) technologies have enabled the construction of a micro chemical vapor deposition (μCVD) system for the synthesis of nanomaterials. By means of localized resistive heating via micro-heaters, unique capabilities of the μCVD systems have been utilized to synthesize carbon nanotubes and graphene in this work, including fast stabilization of temperature; rapid exchange of gas species; laminar gas flow due to small Reynolds number; small...

Monolayer Transition Metal Dichalcogenide NanoLEDs: Towards High Speed and High Efficiency

Kevin Han
Ming C. Wu
Ali Javey
Feng Wang
2019
On-chip optical interconnects promise to drastically reduce energy consumption compared to electrical interconnects, which dominate power dissipation in modern integrated circuits (ICs)One key requirement is a low-power, high-efficiency, and high-speed nanoscale light source. However, existing III-V semiconductor light sources face a high surface recombination velocity (SRV ~ 10...