Engineering Tissues Esther Johnson Physics, Del Rio High School Dr. Alvin Yeh, Associate Professor of Biomedical Engineering Dr. Arne Lekven, Associate Professor of Biology
Transcript
Slide 1
Esther Johnson Physics, Del Rio High School Dr. Alvin Yeh,
Associate Professor of Biomedical Engineering Dr. Arne Lekven,
Associate Professor of Biology
Slide 2
Noninvasive High resolution 3D Images Two Photon Fluorescence
Second Harmonic Generation (SHG) Setup
Slide 3
Embryos are large, robust and transparent Easily observed
Embryonic development occurs rapidly Embryos are easily
manipulated
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Yuqiang Bai - Biomechanics Macroscopic Properties of Engineered
Tissue Microscopic Properties of Extracellular Matrix Various
stretch ratio 1.0:1.0 1.1:1.01.1:1.1 1.2:1.2 1.2:1.1 Photos
courtesy of Yuqiang Bai
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Connecting molecular and cellular biology Biomechanics
Engineered Tissues Stem cell replacement therapy Cancer research
Various other biomedical arenas
Slide 8
TAKS Science Objective 5 Physics TEKS c.3.E, F c.6.B,E
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Research: focus on biomechanics Correlation Elasticity Hookes
law Test the biomechanical properties of engineered skin tissue
Photo courtesy of
http://hyperphysics.phy-astr.gsu.edu/hbase/permot2.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/permot2.html
Slide 10
Memory metal spring.wmv
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Hook Activity: Demonstration of Nitinol Spring vs. Regular
Spring Ask students why there was a difference Notes on Elasticity
and Hookes Law Homework (research assignment) Students must go home
and research Nitinol springs
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Elasticity: the property of a substance that enables it to
change its length, volume, or shape in direct response to a force
effecting such a change and to recover its original form upon the
removal of the force (dictionary.com) Hookes Law or Elasticity F =
-kx F = restoring force exerted by the spring k = spring constant x
= displacement of the spring end from its equilibrium position
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Hookes Law computer simulation Homework: Hookes Law practice
problems
http://phet.colorado.edu/sims/mass-spring-lab/mass-spring-lab_en.html
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Hookes Law Lab PowerPoint on my summer research experience
Photo courtesy of Wikipedia Photo courtesy of JL Stanbrough
http://www.batesville.k12.in.us/physics/phynet/mechanics/newt
on3/Labs/SpringScale.html
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Stretchiest skin - Guinness World Record2.wmv
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Engineering Challenge: design a mechanism to test the stretch
vs. strain on skin-like materials compare the graphs from
engineering challenge with graphs from the Hookes Law lab
Background: Human Skin Must be elastic If not, it would tear Photo
courtesy of exorgroup inc.
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Can synthetic skin handle the same kinds of stressors as its
biological counterparts? Human skin is considered viscoelastic
meaning it demonstrates both viscous and elastic properties while
it is deformed Graph courtesy of
http://www.engin.umich.edu/class/bme456/ligten/ligten.htmhttp://www.engin.umich.edu/class/bme456/ligten/ligten.htm
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Students must design a mechanism to compare the various skins
to identify which most closely resembles human skin Photos courtesy
of http://www.purdue.edu/uns/html4ever/0002.Badylak.SIS.html and
http://childrenshospital.org/newsroom/Site1339/mainpageS1339P223.htmlhttp://www.purdue.edu/uns/html4ever/0002.Badylak.SIS.html
http://childrenshospital.org/newsroom/Site1339/mainpageS1339P223.html
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The stress/pull on the fabric must be equally distributed over
a cross-section Material must be immobilized on the other side
Material cannot be torn or the test has failed Students must decide
which material presents a stress-strain graph which most closely
resembles human skins stress- strain graph.
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Various material squares (wool, spandex, cotton, rubber,
leather, etc) Ruler Hanging Mass Set Wood blocks Pulley apparatus
Cardboard Masking tape Wire hangers Paper clips
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Post-Test (identical to pretest) Closure/ Discussion
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Students will Be able to manipulate the Hookes Law equation.
Analyze and verify Hookes Law. Explore the field of Biomedical
Engineering Identify practical applications of physics in
engineering Design a Biomechanical testing device Evaluate and rank
the biomechanical properties of various materials