Biology and Biomimetic Materials Commons^™

Artificial Alveolar-Capillary Membrane On A Microchip, Keith Male

Materials Engineering

A microfluidic device was synthesized out of polydimethyl siloxane (PDMS) to simulate the structure of the alveolar-capillary interface of the human lung. Soft lithography techniques were used to build a mold structure out of SU-8 epoxy at heights ranging from 30µm to 110 µm on a silicon substrate, with the 70 µm structure working the best. A mixture of 10:1 Sylgard 184 elastomer was then cast using the mold, and cured at a temperature of 80^oC. For the porous membrane, the PDMS was spun on at 6000rpm for 30 seconds using a spin coater to produce a membrane …

Nanocharacterization Of Porous Materials With Atomic Force Microscopy, Yasemin Kutes

Master's Theses

Scanning Probe Microscopy techniques have proven very useful in the investigation of porous nanostructured surfaces. Especially, Atomic Force Microscopy (AFM) has been widely used due to its compatibility with non-conducting surfaces. In particular, AFM often complements other techniques like scanning and transmission electron microscopy by providing quantitative surface information coupled with nanoscale spatial resolution. Its ability to operate in fluid is also important, as this allows researchers to mimic the physiological environment of biological materials and systems. In this work, two main types of porous materials are studied with AFM, including Phosphoric Acid Fuel Cell (PAFC) electrode catalyst layers, and …

Determining A Method For Rendering Low Cost Cdse(Zns) Core(Shell) Quantum Dots Aqueous Soluble Via Amphiphilic Polymer Wrapping, Patrick Mcbride

Materials Engineering

Herein is described the procedure of two amphiphilic polymer wrapping techniques that may be employed for obtaining aqueous soluble quantum dots (QDs) for use in biological fluorescent imaging applications. The advent of QDs has led to new nanoscale fluorescent materials that exhibit unparalleled quantum yields (QYs), high resistance to photobleaching, tunable emissions, and
absorption over a large optical range. However, the QD synthesis employed here at Cal Poly to obtain bright, photostable CdSe(ZnS) core(shell) QDs involves the use of organic solvents and surfactants, leading to hydrophobic QDs. Since all of biology relies on aqueous solubility, this hydrophobicity creates a major …

Artificial Muscle Project: Process Development Of Polydimethyl Siloxane Thin Films For Use In Dielectric Electroactive Polymer Artificial Muscle Actuators, Vincent J. Gayotin, Richard W. Morrison, Paul A. Preisser

Materials Engineering

An artificial muscle design was created founded on the principles of a dielectric electroactive polymer (DEAP), which is fundamentally similar to a capacitor. A polydimethyl siloxane (PDMS)-based elastomer, Sylgard 184 from Dow Corning, was chosen for the design and spun coat onto polystyrene (PS) Petri dishes at varying speeds to create a thin film, using speeds of 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm, and 6000 rpm. The film thicknesses were measured optically through use of a microscope with coupled computer imaging software to generate a characteristic curve of film thickness to spin speed, achieving a minimum film thickness …

Processing Pdms Gecko Tape Using Isopore Filters And Silicon Wafer Templates, Boris Luu

Materials Engineering

Gecko tape was processed through nanomolding involving two types of templates. One template was a Millapore Isopore polycarbonate membrane filter and the other template was an n-type silicon wafer processed to include four different pore diameters. These pore diameters were 20, 40, 80, and 160 microns. AutoCAD was used to design to a mask to be used later during photolithography. Two n-type wafers were sputtered with aluminum, underwent photolithography, and then etched using reactive ion etching. A template was placed into a Petri dish and Sylgard 184 polydimethylsiloxane (PDMS) was poured on the template. Once the PDMS cured,   the 1 …

Assessment Of Electrospinning As An In-House Fabrication Technique For Blood Vessel Mimic Cellular Scaffolding, Colby M. James

Master's Theses

Intravascular devices, such as stents, must be rigorously tested before they can be approved by the FDA. This includes bench top in vitro testing to determine biocompatibility, and animal model testing to ensure safety and efficacy. As an intermediate step, a blood vessel mimic (BVM) testing method has been developed that mimics the three dimensional structure of blood vessels using a perfusion bioreactor system, human derived endothelial cells, and a biocompatible polymer scaffold used to support growth of the blood vessel cells. The focus of this thesis was to find an in-house fabrication method capable of making cellular scaffolding for …

Evaluating The Electrical Response Of Polyaniline To Mechanical Strain, Matthew L. Goebel

Master's Theses

This thesis focuses on the electrical output of polyaniline films subjected to uniaxial strain in hydrochloric acid solutions. Polyaniline belongs to novel class of materials known as conducting polymers. Alternating single and double bonds in the backbone of conducting polymers allow them to transmit electric charge when they are doped with negatively charged ions. Modifying the degree of doping and other electrical/chemical treatments allow conducting polymers to exhibit conducting, semi-conducting, or insulating electrical properties. Resilient mechanical properties, good processability, and low cost make conducting polymers good candidates for applications traditionally held by metals and semi-conductors.

When tensile strain is applied …