tracey atkinson, patrick steiner, low rui hao , and lim yao chong
DESCRIPTION
Tracey Atkinson, Patrick Steiner, Low Rui Hao , and Lim Yao Chong. Mimicking the Composite Structure of Spider Silk to Produce a material with high tensile strength and extensibility. Spider Dragline Silk. Spider web material that makes up the main “axels” of orb weaver spider webs - PowerPoint PPT PresentationTRANSCRIPT
MIMICKING THE COMPOSITE STRUCTURE OF
SPIDER SILK TO PRODUCE A MATERIAL WITH HIGH
TENSILE STRENGTH AND EXTENSIBILITYTracey Atkinson, Patrick Steiner,
Low Rui Hao, and Lim Yao Chong
Spider Dragline Silk Spider web material that makes up the
main “axels” of orb weaver spider webs High tensile strength and very extensible
Structure of Spider Silk Has a composite structure:
20% crystalline regions80% highly elastic substances
Extendible regions connect crystalline regions to produce the amazing properties of spider silk
Applications of Spider Silk Range from biomedical uses, like
ligaments and sutures, to bullet proof vests and parachutes
Spider silk is not used because it is not readily available and there is no method to mass produce it
Project Objective To create a material with both high tensile strength
and elasticity by mimicking the composite structure of spider silk.
Hypothesis By combining the optimal electrospinning method and
optimal ratio of keratin and elastin, we can create a composite mat with high tensile strength and extensibility comparable to that of spider dragline silk.
Keratin and Elastin
Keratin:a material that provides strength in
biomaterials such as nails, bird beaks, horns, etc.
Biodegradable
Has same beta-sheet composition as spider silk
Elastin:A material that provides elasticity to
artery walls, lung tissue, skin, ligaments, etc.
Biodegradable
More elastic than spider silk
ElectrospinningA polymer is dissolved and placed in a syringe
The solution is charged with a high voltage
The high voltage creates anelectric field that causes the polymer to be spun out in thinthreads to a collector plate
A fibrous mat is formed
Methodology Part 1
AOS: optimize the spinning of keratin and elastin separately
HCI: verify the AOS results after break Part 2
AOS: determine the best method for combining keratin and elastin
HCI: determine the best ratio of elastin to keratin
Part 1 Optimize the conditions for
electrospinning keratin and elastin individuallyVoltageSolventsFlow rateDistance to collector plate
The optimal conditions found will be kept constant in Part 2 of the experiment
AOS Will try multiple variations on
electrospinning, while keeping the ratio of elastin to keratin constant, to produce the material with properties most similar to spider silk
Will use a consistent ratio of elastin to keratin yet to be determined
AOS-VariablesIndependent variable:
Method for combining elastin and keratin
Dependent variable: Tensile strength and extensibility of fibrous
mat.Control Variables(constants):
Ratio of elastin to keratin, concentration of separate polymer solutions, voltage, flow rate and distance from the collector plate.
AOS Method 1 The syringes will be placed on opposing
sides of a rotating collector plate Has been found to produce
homegenous mats of multiple polymers
AOS Method 2 The syringes will be placed on the same
side of a stationary collector plate
AOS Method 3 We will attempt to mix the polymers in
one solution, and spin them from the same syringe
Will be attempted if keratin and elastin can be put into the same solution
HCI Will vary the ratio of elastin to keratin,
while keeping method constant, to produce the properties most similar to that of spider silk
Will use AOS Method 2(parallel syringes) for all tests
HCI-VariablesIndependent variable:
Ratio of volume of Keratin solution to Elastin solution used during electrospinning.
Dependent variable: Tensile Strength and Extensibility of Fibrous
mat.Control Variables(constants):
Method of electrospinning, concentration of separate polymer solutions, voltage, flow rate and distance from the collector plate.
AOS: Optimizing Concentration, Flow Rate, Voltage and Solvent for electrospinning Keratin & Elastin
HCI: Duplicating results with a smaller range of independent variables
AOS: Vary Methods of electrospinning
HCI: Vary Ratio of volume of keratin to elastin solution during electrospinning.
Carry out electrospinning with 5 extreme and sparse ratios (Independent Variable).
Measure Tensile strength and Extensibility of results (Data) by sending fibrous mats to NUS.
From data collected, extrapolate the approximate range of optimal ratio. Carry out electrospinning for the approximate range.
Measure Tensile strength and Extensibility of results (Data) by sending fibrous mats to NUS
Optimal Ratio is found.
Most suitable method is found.
Combine both optimal ratio & most suitable method to create a fibrous mat that could mimic spider dragline silk
Timeline
November to January
•Optimize the conditions for electrospinning keratin and elastin
February to April
•Test the different methods of combining elastin and keratin
April to June •Finalize results and
send for tensile testing
January to February
•Verify the optimal conditions for spinning keratin and elastin separately
March to July
•Find the optimal ratio for combining elastin and keratin
July to August
•Send for tensile testing and finalize results
Combining Results If results for ratio are found early
enough, the optimal method and optimal ratio will be combined in one final test to see if we were successful in mimicking spider silk