Digital Commons Network^™

Architected Polymer Foams Via Direct Bubble Writing, Claas Willem Visser, Dahlia N. Amato, Jochen Mueller, Jennifer A. Lewis

Student Publications

Polymer foams are cellular solids composed of solid and gas phases, whose mechanical, thermal, and acoustic properties are determined by the composition, volume fraction, and connectivity of both phases. A new high-throughput additive manufacturing method, referred to as direct bubble writing, for creating polymer foams with locally programmed bubble size, volume fraction, and connectivity is reported. Direct bubble writing relies on rapid generation and patterning of liquid shell–gas core droplets produced using a core–shell nozzle. The printed polymer foams are able to retain their overall shape, since the outer shell of these bubble droplets consist of a low-viscosity monomer that …

Design Of A New 3d‐Printed Joint Plug, Lobat Tayebi, Zhanfeng Cui, Hua Ye

School of Dentistry Faculty Research and Publications

This paper introduces a kit of parts as a novel three‐dimensional (3D)–printed joint plug, in which each of the parts function cooperatively to treat cartilage damage in joints of the human body (e.g., hips, wrists, elbow, knee, and ankle). Three required and one optional parts are involved in this plug. The first part is a 3D‐printed hard scaffold (bone portion) to accommodate bone cells, and the second is a 3D‐printed soft scaffold (cartilage portion) overlying the bone portion to accommodate chondrocytes. The third part of joint plug is a permeable membrane, termed film, to cover the entire plug to provide …

Open Source Waste Plastic Granulator, Arvind Ravindran, Sean Scsavnicki, Walker Nelson, Peter Gorecki, Jacob Franz, Shane Oberloier, Theresa K. Meyer, Andrew Barnard, Joshua M. Pearce

Michigan Tech Publications

In order to accelerate deployment of distributed recycling by providing low-cost feed stocks of granulated post-consumer waste plastic, this study analyzes an open source waste plastic granulator system. It is designed, built, and tested for its ability to convert post-consumer waste, 3D printed products and waste into polymer feedstock for recyclebots of fused particle/granule printers. The technical specifications of the device are quantified in terms of power consumption (380 to 404 W for PET and PLA, respectively) and particle size distribution. The open source device can be fabricated for less than $2000 USD in materials. The experimentally measured power use …

Vibration Alert Bracelet For Notification Of The Visually And Hearing Impaired, Kelsey Conley, Alex Foyer, Patrick Hara, Tom Janik, Jason Reichard, Jon D'Souza, Chandana Tamma, Cristinel Ababei

Electrical and Computer Engineering Faculty Research and Publications

This paper presents the prototype of an electronic vibration bracelet designed to help the visually and hearing impaired to receive and send emergency alerts. The bracelet has two basic functions. The first function is to receive a wireless signal and respond with a vibration to alert the user. The second function is implemented by pushing one button of the bracelet to send an emergency signal. We report testing on a prototype system formed by a mobile application and two bracelets. The bracelets and the application form a complete system intended to be used in retirement apartment communities. However, the system …

Odx: A Fitness Tracker-Based Device For Continuous Bacterial Growth Monitoring, Venkata V.B. Yallapragada, Uday Gowda, David Wong, Liam O'Faolain, Mark Tangney, Ganga C.R. Devarapu

Cappa Publications

Continuous monitoring of bacterial growth in aqueous media is a crucial process in academic research as well as in the biotechnology industry. Bacterial growth is usually monitored by measuring the optical density of bacteria in liquid media, using benchtop spectrophotometers. Due to the large form factor of the existing spectrophotometers, they cannot be used for live monitoring of the bacteria inside bacterial incubation chambers. Additionally, the use of benchtop spectrometers for continuous monitoring requires multiple samplings and is labour intensive. To overcome these challenges, we have developed an optical density measuring device (ODX) by modifying a generic fitness tracker. The …

Application Of Micro-Scale 3d Printing In Pharmaceutics, Andrew Kjar, Yu Huang

Biological Engineering Faculty Publications

3D printing, as one of the most rapidly-evolving fabrication technologies, has released a cascade of innovation in the last two decades. In the pharmaceutical field, the integration of 3D printing technology has offered unique advantages, especially at the micro-scale. When printed at a micro-scale, materials and devices can provide nuanced solutions to controlled release, minimally invasive delivery, high-precision targeting, biomimetic models for drug discovery and development, and future opportunities for personalized medicine. This review aims to cover the recent advances in this area. First, the 3D printing techniques are introduced with respect to the technical parameters and features that are …

Enhancing Cell Seeding And Osteogenesis Of Mscs On 3d Printed Scaffolds Through Injectable Bmp2 Immobilized Ecm-Mimetic Gel, Farahnaz Fahimipour, Erfan Dashtimoghadam, Mohammad Mahdi Hasani-Sadrabadi, Jessica Vargas, Daryoosh Vashaee, Doug Lobner, Tahereh S. Jafarzadeh Kashi, Behnam Ghasemzadeh, Lobat Tayebi

Biomedical Sciences Faculty Research and Publications

Objective

Design of bioactive scaffolds with osteogenic capacity is a central challenge in cell-based patient-specific bone tissue engineering. Efficient and spatially uniform seeding of (stem) cells onto such constructs is vital to attain functional tissues. Herein we developed heparin functionalized collagen gels supported by 3D printed bioceramic scaffolds, as bone extracellular matrix (ECM)-mimetic matrices. These matrices were designed to enhance cell seeding efficiency of mesenchymal stem cells (MSCs) as well as improve their osteogenic differentiation through immobilized bone morphogenic protein 2 (BMP2) to be used for personalized bone regeneration.

Methods

A 3D gel based on heparin-conjugated collagen matrix capable of …

Improving 3d Printed Prosthetics With Sensors And Motors, Rachel Zarin

Honors Projects

A 3D printed hand and arm prosthetic was created from the idea of adding bionic elements while keeping the cost low. It was designed based on existing models, desired functions, and materials available. A tilt sensor keeps the hand level, two motors move the wrist in two different directions, a limit switch signals the fingers to open and close, and another motor helps open and close the fingers. All sensors and motors were built on a circuit board, programmed using an Arduino, and powered by a battery. Other supporting materials include metal brackets, screws, guitar strings, elastic bands, small clamps, …

Mechanical Properties And Applications Of Recycled Polycarbonate Particle Material Extrusion-Based Additive Manufacturing, Matthew J. Reich, Aubrey Woern, Nagendra Gautam Tanikella, Joshua M. Pearce

Michigan Tech Publications

Past work has shown that particle material extrusion (fused particle fabrication (FPF)/fused granular fabrication (FGF)) has the potential for increasing the use of recycled polymers in 3D printing. This study extends this potential to high-performance (high-mechanical-strength and heat-resistant) polymers using polycarbonate (PC). Recycled PC regrind of approximately 25 mm² was 3D printed with an open-source Gigabot X and analyzed. A temperature and nozzle velocity matrix was used to find useful printing parameters, and a print test was used to maximize the output for a two-temperature stage extruder for PC. ASTM type 4 tensile test geometries as well as ASTM-approved …

3d Printed Nmr Spectra: From 1d And 2d Acquisition To 3d Visualization, Michael Bakker, Ben Boyd, Gary A. Meints

College of Natural and Applied Sciences

Visualization of two- dimensional and relaxation NMR spectra can be difficult for students new to the subject. Educators have utilized 3D printing previously to demonstrate concepts such as potential energy surfaces and molecular orbitals, but this technology has yet to be used to create a visual model of NMR data. In order to address this, we have developed an approach for creating 3D printed models of two- dimensional and inversion recovery spectra, which can then be used as an innovative teaching tool. This was done by converting raw FT NMR data into a 3D data graph using Mathematica. This graph …

Single-Step Fabrication Of Electrochemical Flow Cells Utilizing Multi-Material 3d Printing, Glen O'Neil, Shakir Ahmed, Kevin Halloran, Jordyn N. Janusz, Alexandra Rodríguez, Irina M. Terrero Rodríguez

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Here we present methodology for fabricating electrochemical flow cells with embedded carbon-composite electrodes in a single step using simultaneous 3D printing of insulating poly(lactic acid) (PLA) and a commercially available graphene–PLA composite. This work is significant because it is the first demonstration that devices capable of fluid handling and electrochemical sensing can be produced in a single fabrication step using inexpensive equipment. We demonstrate the broad utility of this approach using a channel-flow configuration as an exemplary system for hydrodynamic electrochemistry. Unmodified devices were characterized using hydrodynamic electrochemistry, and behave according to the well-established Levich equation. We also characterized the …

3d Printed Biliary Anatomy For Surgical Planning, Jason Core, Erik Massenzio, Tamar Wasserman, Kevin Xie

Phase 1

Background: Studies demonstrated that 3D-printed livers from CT or MRI data can be accurate models of actual patient anatomy. However, it has yet to be established if 3D printing offers improvements to clinical outcomes in surgery. This project seeks to optimize these applications for use at Jefferson by producing 3D-printed models from patient CT scans to guide liver resection surgeries.

Methods: A liver transplant attending was interviewed about challenges encountered during hepatectomies. A publicly available abdominal computed tomography scan was used to render a liver and its vasculature in 3DSlicer. The liver surface was cut into two halves in MeshMixer …

Engineering Of Bio-Mimetic Substratum Topographies For Enhanced Early Colonization Of Filamentous Algae, Ali Khoshkhoo, Andres L. Carrano, David M. Blersch

Systems Science and Industrial Engineering Faculty Scholarship

No abstract provided.

Student Understanding Of Dna Structure–Function Relationships Improves From Using 3d Learning Modules With Dynamic 3d Printed Models, Michelle E. Howell, Christine S. Booth, Sharmin M. Sikich, Tomáš Helikar, Rebecca Roston, Brain A. Couch, Karin Van Dijk

Department of Biochemistry: Faculty Publications

Understanding the relationship between molecular structure and function represents an important goal of undergraduate life sciences. Although evidence suggests that handling physical models supports gains in student understanding of structure–function relationships, such models have not been widely implemented in biochemistry classrooms. Three-dimensional (3D) printing represents an emerging cost-effective means of producing molecular models to help students investigate structure–function concepts. We developed three interactive learning modules with dynamic 3D printed models to help biochemistry students visualize biomolecular structures and address particular misconceptions. These modules targeted specific learning objectives related to DNA and RNA structure, transcription factor-DNA interactions, and DNA supercoiling dynamics. …

Mechanical Characterizations Of 3d-Printed Plla/Steel Particle Composites, Hozhabr Mozafari, Pengfei Dong, Haitham Hadidi, Michael P. Sealy, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The objective of this study is to characterize the micromechanical properties of poly-L-lactic acid (PLLA) composites reinforced by grade 420 stainless steel (SS) particles with a specific focus on the interphase properties. The specimens were manufactured using 3D printing techniques due to its many benefits, including high accuracy, cost effectiveness and customized geometry. The adopted fused filament fabrication resulted in a thin interphase layer with an average thickness of 3 μm. The mechanical properties of each phase, as well as the interphase, were characterized by nanoindentation tests. The effect of matrix degradation, i.e., imperfect bonding, on the elastic modulus of …

3d Printing Of Hybrid Mos2-Graphene Aerogels As Highly Porous Electrode Materials For Sodium Ion Battery Anodes, Emery Brown, Pengli Yan, Halil Tekik, Ayyappan Elangovan, Jian Wang, Dong Lin, Jun Li

Department of Mechanical and Materials Engineering: Faculty Publications

This study reports a 3D freeze-printing method that integrates inkjet printing and freeze casting to control both the microstructure and macroporosity via formation of ice microcrystals during printing. A viscous aqueous ink consisting of a molecular MoS₂ precursor (ammonium thiomolybdate) mixed with graphene oxide (GO) nanosheets is used in the printing process. Post-treatments by freeze-drying and reductive thermal annealing convert the printed intermediate mixture into a hybrid structure consisting of MoS₂ nanoparticles anchored on the surface of 2D rGO nanosheets in a macroporous framework, which is fully characterized with FESEM, TEM, XRD, Raman spectroscopy and TGA. The resulting …

Data-Centric Technologies: Patent And Copyright Doctrinal Disruptions, Tabrez Y. Ebrahim

Faculty Scholarship

Data-centric technologies create information content that directly controls, modifies, or responds to the physical world. This information content resides in the digital world yet has profound economic and societal impact in the physical world. 3D printing and artificial intelligence are examples of data-centric technologies. 3D printing utilizes digital data for eventual printing of physical goods. Artificial intelligence learns from data sets to make predictions or automated decisions for use in physical applications and systems. 3D printing and artificial intelligence technologies are based on digital foundations, blur the digital and physical divide, and dramatically improve physical goods, objects, products, or systems. …