网络研讨会

ElectroForce Apex 1: 机械性能测试仪 网络研讨会

Overview

Liquid-crystal elastomers (LCEs) uniquely combine molecular ordering with entropic elasticity. The result is a class of anisotropic elastomers with remarkable properties spanning stimuli responsive actuation to exceptional dissipation of mechanical energy.

Our group has recently developed a range of photopolymerizable LCE resins and inks which we 3D print using direct ink writing (DIW) and digital light processing (DLP) technologies. The combination of our chemistries and these 3D printing technologies allows facile production of some of the largest LCE devices ever produced – on a scale finally suitable for real-world applications such as spinal implants and football helmets.

In this webinar, we will briefly introduce LCEs and our 3D printing methods. Next, we will demonstrate our methods and instrumentation that have enabled our fundamental characterization of these exceptional materials. To measure the rate-dependence of DLP-printed LCE lattices, we used compression testing with strain rates ranging from 0.21 to 220 % s-1 and compared the changes in strain energy density and peak stresses with lattices printed from traditional elastomers. With anisotropic DIW-printed LCE devices we studied the dependence of quasi-static (modulus, strain energy density) and dynamic (dynamic modulus and tan delta between 0.1 – 100 Hz) mechanical properties on loading direction. Additionally, using dynamic testing we studied the long-term performance of a semi-crystalling LCE 3D printed spinal device. By subjecting prototype devices to 1 M compressive cycles under physiological conditions we measured the change in mechanical properties and demonstrated our device’s fatigue resistance.

Overall, this webinar covers a range of quasi-static and dynamic mechanical testing methods which we perform using the ElectroForce 3200 instrument to characterize these highly complex and fascinating materials.

About The Speaker

Dr. Chris Yakacki received his Ph.D. in mechanical engineering at the University of Colorado Boulder in 2007. During his graduate studies, he helped co-found Medshape, Inc. – a university-based startup focused on developing novel shape-memory devices. Dr. Yakacki worked as the principal scientist at Medshape from 2007-2011, during which time he helped clear the first shape-memory polymer devices through the USFDA. This includes the morphix suture anchor and exoshape anterior cruciate ligament (ACL) fixation device. He returned to academia in 2012 and joined the faculty at the University of Colorado Denver. He received the prestigious NSF Career Award to investigate liquid-crystal elastomers for biomedical applications. He has published over 50 peer-reviewed publications and raised over $2M in federally funded research. He is dedicated to once again translating his research from the university into the marketplace with Impressio – another university-based startup now focused on commercializing liquid-crystal elastomers.

Dr. Devesh Mistry interests lie in the fundamental physics behind the mechanical properties of anisotropic and functionalised polymers. I completed my PhD in 2018 in the School of Physics and Astronomy at the University of Leeds, UK. Supervised by Professor Helen Gleeson, my PhD focused on unresolved inconsistencies in our knowledge of LCE mechanical behaviours. In this process I discovered the inherent negative Poisson’s ratio (auxetic) behaviour of LCEs.

Following my PhD, I joined Prof. Chris Yakacki’s group at the University of Colorado Denver as a postdoctoral fellow – supported by a Lindemann Trust Fellowship. Here my research has focused on using 3D printing to understand the role of order and disorder in the exceptional dissipative properties of LCEs.

Nicholas Traugutt, a PhD candidate in Mechanical Engineering at the University of Colorado Denver under the tutelage of Prof. Chris Yakacki. My research focuses on how to tailor bulk liquid crystal elastomer (LCE) structures across different length scales (e.g. meso, micro, and macro) to better dissipate mechanical energy. In the course of my research, I have discovered several different molding and manufacturing techniques through the use of additive manufacturing as well as helping to improve synthetic methods for the thiol-acrylate LCE chemistry. One of my greatest achievements to date includes creating a scalable and tailorable method to use digital light processing to 3D print LCE structures that would otherwise be difficult to impossible to fabricate.

In my downtime on campus from researching LCEs, I am often tinkering with 3D printers. My knowledge and abilities with 3D printing led to an opportunity to work as a consultant for 3D printing PEEK, and I have success with 3D printing other engineering polymers such as PPSU.

I currently have six peer-reviewed papers, including a recent publication in Advanced Materials for DLP printing LCEs.

Overview

New product design is expedited by gathering product performance metrics early in the compound development process. These key metrics link to final product performance and answer common questions: How will my product perform in its final application? Is performance guaranteed over the lifetime of the product? Predicting mechanical rigidity, suitability to end-use environmental conditions, and long-term stability empower a compound developer to filter for leading candidates before progressing to expensive pilot and larger scale trials. In this talk, we will introduce several techniques to characterize cured rubber products and link these measurements to final product performance. Some topics will include:

•  Characterizing damping properties and modulus values with dynamic mechanical analysis (DMA)
•  Measuring fatigue and heat build-up testing of rubber compounds
•  Performance in corrosive and pressurized environments with thermal gravimetric analysis (HP-TGA)

About The Speaker

Sadegh Behdad is an Applications Engineer at TA Instruments, supporting ElectroForce product line. Sadegh has a PhD in Materials Science and Engineering from Florida International University. He earned his BSc and Masters in Polymer Engineering from Amirkabir University of Technology. Prior to joining TA Instruments, Sadegh worked as a Sr. Materials Scientist at Magic Leap. At Magic Leap, he supported material design and development teams on selection of material candidates and testing various materials and components for wearable virtual retinal display applications.

Overview

Durability testing of Medical Devices is crucial for validation of performance and safety and often becomes an important element of regulatory submissions. As such, devices undergo a range of extensive fatigue characterization to support lifetime predictions for the design, optimization and approval for safe and life-changing device solutions. A variety of common standards-based test methods will be presented including example or published test data for each.

About The Speaker

Sadegh Behdad is an Applications Engineer at TA Instruments, supporting ElectroForce product line. Sadegh has a PhD in Materials Science and Engineering from Florida International University. He earned his BSc and Masters in Polymer Engineering from Amirkabir University of Technology. Prior to joining TA Instruments, Sadegh worked as a Sr. Materials Scientist at Magic Leap. At Magic Leap, he supported material design and development teams on selection of material candidates and testing various materials and components for wearable virtual retinal display applications.

Overview

This presentation will introduce a range of biomaterials test applications where mechanical test instruments are assisting researchers and engineers in gaining a better understanding of native and artificial tissues. Tissue characterization often leverages test techniques designed to measure quasi-static and dynamic properties of human or animal model tissues. These measurements can be used to evaluate drug-, hormone- or age-related changes in tissues such as bone, cartilage, tendon, ligament, vessels, eyes and heart valves. These properties can also be used as baseline or reference data for medical device development.

About The Speaker

Muhammad Haris is Application Engineer for TA Instruments ElectroForce based near Frankfurt, Germany. He specialized in ElectroForce mechanical test instruments and engages with customers on their testing needs related to the application of ElectroForce products and puts forward broad-ranging solutions. He holds a master’s degree in Advanced Materials & Processes. Prior to joining TA Instruments, Haris has worked with Procter & Gamble for about 2 years on analytical development and characterization of electric shavers’ blades.

 
 

Overview

Durability testing of Medical Devices is crucial for validation of performance and safety and often becomes an important element of regulatory submissions. As such, devices undergo a range of extensive fatigue characterization to support lifetime predictions for the design, optimization and approval for safe and life-changing device solutions. A variety of common standards-based test methods will be presented including example or published test data for each.

About The Speaker

Sadegh Behdad is an Applications Engineer at TA Instruments, supporting ElectroForce product line. Sadegh has a PhD in Materials Science and Engineering from Florida International University. He earned his BSc and Masters in Polymer Engineering from Amirkabir University of Technology. Prior to joining TA Instruments, Sadegh worked as a Sr. Materials Scientist at Magic Leap. At Magic Leap, he supported material design and development teams on selection of material candidates and testing various materials and components for wearable virtual retinal display applications.

 

Overview

This presentation will introduce a range of biomaterials test applications where mechanical test instruments are assisting researchers and engineers in gaining a better understanding of native and artificial tissues. Tissue characterization often leverages test techniques designed to measure quasi-static and dynamic properties of human or animal model tissues. These measurements can be used to evaluate drug-, hormone- or age-related changes in tissues such as bone, cartilage, tendon, ligament, vessels, eyes and heart valves. These properties can also be used as baseline or reference data for medical device development.

About The Speaker

Muhammad Haris is Application Engineer for TA Instruments ElectroForce based near Frankfurt, Germany. He specialized in ElectroForce mechanical test instruments and engages with customers on their testing needs related to the application of ElectroForce products and puts forward broad-ranging solutions. He holds a master’s degree in Advanced Materials & Processes. Prior to joining TA Instruments, Haris has worked with Procter & Gamble for about 2 years on analytical development and characterization of electric shavers’ blades.

 
 

Overview

During the formulation and manufacturing of polymeric materials for medical devices, the materials go through multiple stages and undergo many transformations. At each of these stages new additives might be added or the material is exposed to physical factors like heat which impacts the chemical nature of the ingredients. Subsequently, during the final product lifecycle these compounds might migrate into the patient body causing unintended harmful consequences. ISO 10993 regulations include the requirements for chemical testing of medical devices to demonstrate the possible migration and identification of the migrating species. High resolution mass spectrometry and scientific data systems can help analysts meet the regulatory requirements and ensure patient safety.

About The Speaker

Dr. Cabovska holds a research degree in analytical chemistry and has over 10 years of experience in extractables and migration application. Dr. Cabovska is currently a senior business development manager at Waters Corporation, located in Milford, MA – USA where she actively collaborates with customers on providing comprehensive materials characterization solutions across extractables and migration testing applications. Before joining Waters, Dr. Cabovska focused her work on Bioanalytical method development and validations for therapeutic drug monitoring and extractable and leachable studies in packaging.

 

Chris Yakacki: Characterization of Active Shape-Memory Polymers

The field of stimuli-sensitive polymers has grown rapidly over the past decade. Actively-moving polymers have gained attention and have been proposed for use in applications from shape-changing biomedical devices to morphing structures. This webinar covers the basics of characterizing shape-memory polymers using thermo-mechanical equipment, such as the Q800 and ElectroForce 3200. The details of the shape-memory cycle and dynamic-mechanical analysis are explained and results from several studies are highlighted that demonstrate how these materials can be investigated and explored.

About the Speaker

Christopher Yakacki is an assistant professor in the department of mechanical engineering at the University of Colorado (CU) Denver. Chris earned his PhD from CU Boulder in 2007, which focused on the thermo-mechanics of shape-memory polymers. He helped co-found MedShape, Inc., a biomedical device company in Atlanta, GA and served as the principal scientist for MedShape from 2008-2011. During this time, MedShape cleared several innovative shape-memory polymer and alloy medical devices through the USFDA. In 2012, Chris joined the faculty at CU Denver. He has since been developing new methods of synthesizing liquid-crystalline elastomers and characterizing their actuation and viscoelastic behavior. He also serves as an advisor and consultant for several biomedical device companies that focus on smart-polymer devices. Chris has published over 33 peer-reviewed journal articles and has been awarded over $2M in small business and academic research grants.