Ali Javey (Advisor)

Research Advised by Professor Ali Javey

Javey Group:  List of Projects | List of Researchers

BPN898: A Wearable Microfluidic Sensing Patch for Dynamic Sweat Secretion Analysis

Hnin Y. Nyein
2018

Wearable sweat sensing is a rapidly rising research driven by its promising potential in health, fitness and diagnostic applications. Despite the growing field, major challenges in relation to sweat metrics remain to be addressed. These challenges include sweat rate monitoring for its complex relation with sweat compositions and sweat sampling for sweat dynamics studies. In this work, we present a flexible microfluidic sweat sensing patch that enhances real-time electrochemical sensing and sweat rate analysis via sweat sampling. The device contains a spiral-patterned microfluidic...

BPN901: Roll-to-Roll Gravure Printed Electrode Arrays for Non-Invasive Sensing Applications

Mallika S. Bariya
2018

As recent developments in noninvasive biosensors spearhead the thrust towards personalized health and fitness monitoring, there is a need for high throughput, cost-effective fabrication of flexible sensing components. Towards this goal, we are working on roll-to-roll (R2R) gravure printed electrode arrays that are robust under a diverse range of electrochemical sensing applications, including detection of ions, metabolites, and heavy metals in human perspiration. R2R printed arrays that are suitable for continuous, in situ use are a key step towards enabling large-scale production of...

BPN891: Dopant-Free Asymmetric Heterocontact Silicon Solar Cells with >20% Efficiency

Wenbo Ji
2019

A salient characteristic of solar cells is their ability to subject photo-generated electrons and holes to pathways of asymmetrical conductivity—‘assisting’ them towards 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. A progressive approach to circumvent these issues involves the replacement of...

BPN458: Optical Antenna-Based nanoLED

Kevin Han
Seth Fortuna
Matin Amani
2019

Spontaneous emission has been considered slower and weaker than stimulated emission. As a result, light-emitting diodes (LEDs) have only been used in applications with bandwidth 1 GHz. Spontaneous emission is inefficient because the radiating dipole is much smaller than the wavelength and such short dipoles are poor radiators. By attaching an optical antenna to the radiating dipole at the nanoscale, the emission rate can be significantly increased, enabling high modulation bandwidths theoretically 100 GHz. This project focuses on the physical demonstration of this new type of...

BPN770: Chemical Sensitive Field Effect Transistor (CS-FET)

Niharika Gupta
2019

Silicon IC-based fabrication processing will be used to develop novel compact gas sensors that, unlike current sensors, will operate at room temperature, consume minimal power, exhibit superior sensitivity, provide chemical selectivity and multi-gas detection capabilities, and offer the prospect of very low-cost replication for broad-area deployment. We name this device structure “Chemical Sensitive FET” or “CS-FET.” The operation of the CS-FET involves transistor parametric differentiation under...

BPN928: Black Phosphorous Based Infrared Light Emitting Diodes

Niharika Gupta
2019

Two-dimensional (2D) materials such as MoS2 and black phosphorous (bP) have shown promise for high performance optoelectronic and electronic applications, due to their naturally terminated surfaces. Unlike the majority of 2D materials, which are only direct bandgap at the monolayer limit, bP maintains a direct bandgap for all thickness, which ranges from 1.4 to 0.3 eV. This property can be leveraged to demonstrate light emitting diodes (LEDs) based on bP/MoS2 heterostructures. High EQE can be...

BPN909: High Quality Synthetic Monolayer Semiconductor

Hyungjin Kim
2019

In recent years, there have been tremendous advancement in the growth of monolayer transition metal dichalcogenides (TMDCs) by chemical vapor deposition (CVD). However, obtaining high photoluminescence quantum yield (PL QY), which is the key figure of merit for optoelectronics, is still challenging in the grown monolayers. Specifically, the as-grown monolayers often exhibit lower PL QY than their mechanically exfoliated counterparts. In this work, we demonstrate synthetic tungsten diselenide (WSe2)...

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...