Ioannis D. Chasiotis

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Engineering complex tissues such as the tendon-to-bone insertion sites require a strong and tough biomimetic material system that incorporates both mineralized and unmineralized tissues with different strengths and stiffnesses. However, increasing strength without degrading toughness is a fundamental challenge in materials science. Here, we demonstrate a(More)
—An apparatus has been designed and implemented to measure the elastic tensile properties (Young's modulus and tensile strength) of surface micromachined polysilicon specimens. The tensile specimens are " dog-bone " shaped ending in a large " paddle " for convenient electrostatic or, in the improved apparatus, ultraviolet (UV) light curable adhesive(More)
A novel method to perform nanoscale mechanical characterization of highly deformable nanofibers has been developed. A microelectromechanical system (MEMS) test platform with an on-chip leaf-spring load cell that was tuned with the aid of a focused ion beam was built for fiber gripping and force measurement and it was actuated with an external piezoelectric(More)
Experimentation at the micron level requires specific tools and methods. It will be illustrated how some of these tools have to be combined to achieve this goal. Because the determination of strains at the micron and nanoscales has been explored with the aid of probe microscopy, attention needs to be devoted to the limitations of digital image correlation.(More)
A micromechanical modeling procedure is developed to predict the viscoelastic properties of a graphite nanoplatelet/epoxy composite as a function of volume fraction and nanoplatelet diameter. The predicted storage and loss moduli from the model are compared to measured values from the same material using Dynamical Mechanical Analysis, nanoindentation, and(More)
1. Abstract In this report, design, operation principles and finite elements analysis of a novel MEMS based mechanical testing platform for highly deformable nanofibers and nanowires is presented. Mechanical actuation is accomplished through a group of five thermal actuators by sequencing electrical inputs to a coordinated grip-release and pulling(More)
1 ABSTRACT A method to measure the mechanical behavior of Pt thin films was developed. It employs high magnification optical microscopy and Digital Image Correlation to extract sub-micron (100 nm local displacement resolution) deformation fields in free-standing thin films and calculate their elastic/plastic properties as a function of strain rate. In this(More)
The effect of strain rate on the mechanical behavior of gold thin-films for RF-MEMS applications was examined. Microscale, free-standing, dog bone shaped specimens were subjected to uniaxial tension tests at strain rates ranging between 10-6 s-1 and 10-3 s-1 via a custom built testing apparatus. The specimens, fabricated using e-beam evaporation, had gage(More)
Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden(More)
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