Pharma
Chao, Eva, Jae Wan, Ben, Janice
We use organic vapor jet printing (OVJP) to control the form (xtalline vs amorphous) and morphology (films vs particles, particle size and shape) of active pharmaceutical ingredients (APIs). The process includes heating the material to produce vapor, then using nitrogen to jet the API vapor at a substrate where it condenses.
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Each grad student on this project has settled into an application area that interests them. Fundamentals of the process and its resulting structures span all applications, which means a team effort to understand and control the process, with each person bringing their own take on how to use the resulting products.​
Dissolution rate (Chao). Most APIs are poorly soluble. Reducing particle size, producing an amorphous form, and/or co-depositing APIs with other APIs or other non-active ingredients can make APIs dissolve faster.
​​Coating non-planar substrates for non-oral dosing applications (Jae Wan). OVJP doesn't produce loose powder, it deposits onto a surface where it sticks. Jae is taking advantage of that characteristic to deposit dye on cotton (to eliminate water-intensive dying processes) and to engineer non-oral drug delivery devices (patches, implants, etc).
Low drug-loading oral dosage forms (Eva). Measuring small amounts of powder is hard. OVJP takes advantage of the inherent properties of vapor to precisely meter small amounts into specified locations. Eva coats dissolvable films and non-active ingredients with small amounts of API to produce orodispersible films and/or conventional tablets with very small amounts of API.
OLEDS
Binyu
Organic light emitting devices (OLEDs) are widely used in display application. However they are barely seen in the lighting application. The key problem for OLEDs used as lighting source is the trade-off between high brightness and long lifetime. Lighting application requires high brightness, while OLEDs degrade fast under high brightness.
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Binyu's research focuses on introducing high aspect ratio corrugated substrates to solve this trade-offs. OLEDs stacks are usually 400 - 500 nm thick, while the corrugation is micron large. Therefore all stacks could sit on top of the corrugation, expanding the active area of OLEDs, reducing current density and therefore improving efficiency and lifetime.
Shoulder Sensor
Dan, Yinchi
We work with kirigami based medical sensors that measure an individual’s movements through PEDOT:PSS polymer based strain gauges. We can add dopants or vary the deposition method to change the polymer’s overall electrical resistance, and its response to strain. We are working towards implementing this technology in the fields of medicine and motion capture techniques.​
Deposition Methods and Patterning (Dan): Daniel is currently working towards developing ways of patterning PEDOT:PSS on the kirigami sensor so that it will improve and increase the consistency of the strain response. The patterning methods include stamping and electrohydrodynamic printing which can both produce features smaller than a millimeter.
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Dopant Effects and Performance (Yinchi): Yinchi is currently investigating the effects of varying dopant compositions, including silver nanoparticles and organic solvents, on the strain sensitivity of the PEDOT:PSS strain gauges. Additionally, he is also conducting reliability assessments to ensure consistent sensor performance across different conditions.
strain
gauges
Photonic Crystals
Yash
Photonic crystals are materials with a periodically varying refractive index, which enables precise control over their interaction with light. By optimizing through design and fabrication, we can control which wavelengths of light are transmitted or reflected.
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This project centers on polymer-based photonic crystal fibers that can be woven directly into fabrics. These fibers serve as unique optical barcodes when exposed to near-infrared light, offering valuable information about the textiles they are integrated into, which can be highly beneficial for improving recycling processes and preventing counterfeiting.
Using optical simulations and exploring how factors such as refractive index contrast, layer thickness, and photonic crystal periodicity influence the photonic properties of these fibers, Yash is aiming to tailor their functionality and expand the scope of applications.
Kirigami inspired cell platforms
Katie
Within human biological systems, cells are signaled by a variety of mechanical forces and those interactions may provide insights to diseases. We are designing in vitro cell scaffolds that will mimic the forces experienced by cells in vivo. In addition to the forces experienced, there may be electrical stimulation and/or unique topography. Current efforts are focusing on the curvature and tensile forces in action in the respiratory system using thin plastic membranes and 3D printed frames.