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Innovation Grants Program, 2009

NANOWIRE-BASED PIEZO-OPTO-MECHANICAL BIO-SENSORS

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Ritesh Agarwal
Department of Materials Science & Engineering

Gianluca Piazza
Department of Electrical and Systems Engineering

We will assemble a nanowire-based piezo-opto-mechanical sensing device which will selectively detect biological analytes with unprecedented resolution. We will exploit the small mass (10-50 fg) of the piezoelectric nanowire to devise a balance capable of weighing individual biomolecules. The biggest challenge in demonstrating NanoElectroMechanicalSystems (NEMS)-based sensing devices is the readout mechanism; nanoscaling of the device makes it extremely sensitive but at the expense of drastically reduced electrical output signals. To address this fundamental challenge we propose a unique scheme based on piezoelectrically-actuated nanowires monolithically integrated with an optics-based read out scheme by utilizing the near-field optical coupling between the two nanowire resonators.

 

Multi-functional nano-particles and -patterns for nano-resolution fluorescence imaging of spatiotemporal and mechanical aspects of T-cell stimulation

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Schematic showing interaction of biological cell with laterally structured surface (A) exemplified by functionalized diblock-copolymer patterns (B) or colloidal monolayers (C)

Tobias Baumgart
Departments of Chemistry
baumgart@sas.upenn.edu
http://www.sas.upenn.edu/~baumgart/baumgartlab/Home_Page.html

Janis K. Burkhardt
Department of Pathology and Laboratory Medicine
Associate Professor
jburkhar@mail.med.upenn.edu
http://www.med.upenn.edu/camb/faculty/cbp/burkhardt.html

Spatial phenomena related to immune cell stimulation have recently emerged as cutting-edge research interest. While stimulation through single receptor pathways is increasingly being understood, research focus is shifting to understanding co-stimulation via multiple types of receptors. We are applying diffraction-limit-breaking fluorescence imaging techniques such as single particle tracking and photoactivation light microscopy (PALM) to the investigation of immune cells interacting with nano-patterned surfaces. Patterning will be achieved primarily by self-assembly techniques. Our aim is to elucidate spatio-temporal regulatory processes that influence T-cell stimulation through integrin as well as T-cell receptor ligands.

 

 

Imprinted Biomimetic Catalysts for Cellulose Hydrolysis

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Schematic representation of molecular imprinting process.

I-Wei Chen
Department of Materials Science & Engineering     
iweichen@lrsm.upenn.edu
http://www.seas.upenn.edu/mse/fac/chen.html

Scott L. Diamond
Department of Chemical and Biomolecular Engineering
sld@seas.upenn.edu
http://www.seas.upenn.edu/~diamond/director.html

Daeyeon Lee
Department of Chemical and Biomolecular Engineering
daeyeon@seas.upenn.edu
http://www.seas.upenn.edu/cbe/lee.html

One alternative to petroleum-based fuels is corn-based ethanol. There are growing concerns, however, about the feasibility and potential environmental impact of using a major food crop to produce ethanol. A much more sustainable and environmentally friendly source of ethanol is cellulose, which is a major component of plants. Hydrolysis of cellulose would generate glucose, which subsequently can be fermented to ethanol. Hydrolysis of cellulose, however, is difficult to achieve, and is currently the rate-limiting step in the cellulose-to-ethanol conversion. In fact, only biological enzymes with very specific structures are known to achieve cellulose hydrolysis efficiently. These enzymes, however, are not very stable and are expensive preventing their widespread use for cellulose hydrolysis. We propose to develop robust biomimetic solid catalysts that can hydrolyze cellulose and its subunits. This goal will be achieved by molecularly imprinting cellulose and its subunits onto solid catalyst supports. Our strategy combines the efficiency and specificity of protein-based enzymes with the robustness and cost effectiveness of solid catalysts.

 

Electroactive Polymer/Carbon Nanotube Composites as Charge Storage Media for Supercapacitors

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Jorge J. Santiago-Avilés
Department of Electrical and Systems Engineering
santiago@seas.upenn.edu
http://www.ese.upenn.edu/~santiago/home/Welcome.html

Among the several types of energy storage devices, electrochemical capacitors (ECs) also known as supercapacitors or ultracapacitors have gathered increasing attention for applications that demand high operating power levels. Two types of supercapacitors, electrochemical double-layer capacitors (EDLCs) and redox capacitors, can be distinguished based on the way charge is fundamentally stored. While high surface area carbonaceous materials are traditionally used for EDLCs, metal oxides or electroactive polymers (EAPs) typically constitute the electrode materials in redox capacitors. Our research explores the electrodeposition and performance of p- and n-dopable EAPs for redox capacitors, semi-conducting polymer-wrapped carbon nanotube (CNT) compositions for EDLCs, and EAP/polymer-wrapped CNT composites for hybrid symmetrical and asymmetrical supercapacitors. The fabrication of these materials along with their potentiometric and chemical composition properties, impedance characteristics, thermo-mechanical features, redox kinetics, and charge transport properties is studied.

 

 

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info@nanotech.upenn.edu
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