Roya Maboudian (Advisor)

Research Advised by Professor Roya Maboudian

Maboudian Group:  List of Projects | List of Researchers

BPN842: Conductometric Gas Sensing Behavior of WS2 Aerogel

Wenjun Yan
2016

The gas sensing characteristics of a high surface area tungsten disulfide (WS2) aerogel are investigated. Gas sensors are fabricated by integrating a low-density WS2 aerogel onto a low power polysilicon microheater platform to provide control over the operating temperature. The response of the WS2 aerogel-based sensors to NO2, O2, and H2 is investigated with the sensing characteristics indicating p-type behavior. The optimum sensing temperature is found to be about 250 ℃;, when considering sensitivity, power consumption and response time. The role of O2 in H2 and NO2 sensing is...

BPN834: Direct Formation of Pore-Controllable Mesoporous SnO2 for Gas Sensing Applications

Won Seok Chi
Hu Long
2017

Amphiphilic graft copolymer self-assembly provides an effective method to create mesoporous structures that can act as templates for the synthesis of inorganic materials with controlled morphology. In this project, we are using PVC-g-POEM graft copolymer as a template for mesoporous SnO2 fabrication directly onto a microheater platform for gas sensing applications. The sol-gel solutions are composed of PVC-g-POEM and SnO2 precursor with tunable composition allowing the formation of various structures with controllable pore size, and surface area. The mesoporous SnO2 structure is...

BPN813: Novel Hierarchical Metal Oxide Nanostructures for Conductometric Gas Sensing

Ameya Rao
2017

Semiconducting metal oxides have been extensively studied as sensing materials for conductometric gas sensors. Nanostructured metal oxides integrated with miniaturized heating elements have been shown to exhibit particularly high sensitivity while maintaining low power consumption. However, the incorporation of nanostructured metal oxide films onto miniaturized heater-based sensing platforms commonly suffers from uncontrollability in film thickness and microstructure, which reduces sensor performance and fabrication reproducibility. We have developed a controllable and flexible...

BPN878: Scalable Synthesis of Core-Vest Nanoparticles Assisted by Surface Plasmons

Siyi Cheng
Arthur O. Montazeri
2018

Compared with single-component nanocrystals, core-shell nanocrystals show better performance in various areas, such as energy harvesting and storage, catalysis, sensing and functionalized targeted cell therapy. The solution-based fabrication process is the most common strategy for synthesizing core-shell structures. However, the complex and difficult-to-scale fabrication procedures severely reduce their practical applications. Besides, the thermodynamically driven process of the fabrication of core-shell nanostructures possesses several constraints on their size and geometry, the...

BPN835: Silicon Carbide Passivated Electrode for Thermionic Energy Conversion

Steven R. DelaCruz
Zhongtao Wang
2018

In thermionic energy converters (TECs), electrons emitted from a hot electrode (emitter) into a vacuum gap are harvested by a cooler electrode (collector), and then return to the emitter, delivering power to an external load. In this process, TECs convert heat directly into electricity and have the potential to achieve high efficiencies comparable to those of conventional heat engines. We have initiated a collaborative project to develop a microfabricated, close-gap thermionic energy converter that utilizes heat from a combustion source. Potential applications include residential...

BPN790: Two-Dimensional Materials-Based Aerogel on Low-Power Microheater Platform for Gas Sensing Application

Siyi Cheng
David Gardner
2018

There remains a strong need for miniaturized, low power gas sensors that can be deployed in wireless applications for improved environmental protection, health and safety. Aerogels have attracted significant attention in recent years due to their extremely low density, high surface area, low thermal conductivity, weak dielectric permittivity, and high stability. For gas sensing applications, two-dimensional materials offer the highest possible surface area for gas interaction, leading to high sensitivity. However, when materials are integrated into a sensor device, the surface area...

BPN875: Transfer-Free Synthesis of Graphene on Insulating Substrates

Leslie L. Chan
Zhongtao Wang
Yuhui Xie
2018

Graphene has become one of the pinnacles of nanomaterials research, touted for its manifold applications and potential as “the next silicon” in electronics. At this time, integrated production of graphene-based devices remains a barrier, requiring a process that is reliable, large-scale, and compatible with conventional fabrication approaches. One common method for graphene synthesis is chemical vapor deposition (CVD) on metal substrates, which requires a transfer step to target materials (e.g., insulating substrates for device applications). However, this extra transfer step often...

BPN904: Ultrahigh Aspect-Ratio Gold Nanostructure for Electrochemical Sensing in Liquid Media

Yuhui Xie
2019

Electrode surface structure and functional modification with higher catalytic response are of great interest in many technologies. This work aims at designing highly efficient nanostructured gold- based electrochemical catalyst. Using the calixarene-capped gold nanoclusters as the construction unit, we report on the formation of gold films with nanoporous structure via hydrogen-bubble templating under electrochemically reducing conditions. The resulting nanoporous gold (NPG) assembly possesses the highest aspect ratio (defined as the ratio of the pore size to the wall thickness)...

BPN919: SiC-Based Nanostructures for Flexible Devices

Steven R. DelaCruz
Siyi Cheng
2019

Due to their high mechanical robustness, thermal stability, chemical resilience, and breakdown field strength, silicon carbide (SiC)-based nanostructures can be broadly utilized in devices such as field emitters, supercapacitors, and gas sensors. While SiC nanostructures have been widely explored on rigid substrates, their integration on flexible substrates has been limited. Carbon cloth (CC) is an optimal substrate for direct SiC...

BPN927: CeO2/Au Nanostructured Material for Electrochemical Detection of Dopamine

Yuhui Xie
2019

Dopamine (DA) plays a significant role in the central nervous system, the loss of which is linked to various problems, e.g., schizophrenia, drug addiction and Parkinsons disease. Accordingly, the development of sensitive and selective detection method for DA is of great interest. Electrochemical DA detection has gained increasing attention due to its operation simplicity and rapid response. Despite these advantages, electrochemical methods often lack...