Electrospinning of hybrid polymers to mimic spider dragline silk Lim Yao Chong HCI ・ Low Rui Hao HCI ・ Tracey Atkinson AOS ・ Patrick Steiner AOS A joint-project between Singapore’s Hwa Chong Institution and Virginia’s Academy of Science

Background Information Spider Dragline Silk Keratin Elastin Electrospinning It has a High tensile strength and High extensibility. Composite structure of crystalline and elastic regions Provides strength in biomaterials: nails, bird beaks, horns, etc. Biodegradable Has same beta- sheet composition as spider silk Provides elasticity to artery walls, lung tissue, skin, ligaments, etc. Biodegradable More elastic than spider silk Polymer dissolves in volatile solvent and placed in syringe. High voltage causes the polymer to spin into thin threads on to a collector plate.

Collaboration Process Job Division ・ Initial Progress ・ Sustained Communication ・ Consolidation With a given topic, the teams work on coming out with parallel projects: Working towards the same goal Aiding each other in research Independent HCI students flew over to Virginia to plan: Parallel projects Materials & Methodologies Data Collection Method This is to ensure uniformity and consistency Both parties embarked on individual research and shared reviews, discussed problems and shared findings online: Wikispaces group Google Talk (real-time) AOS students flew to Singapore to consolidate findings and tie up loose ends. Prepare for a Presentation & Research Paper to a panel of Singaporean Judges on the research findings

Image of Fibrous Mat ConcentrationRemarks 5% (of keratin+PEO solute by weight) Large amount of beadings, as well as droplets of solutions (i.e. failed) 7%Even mat formed. Fibres have more beading than in 10%, but thinner fibres. 10%Even mat formed. Fibres had least amount of beading. Thicker fibres than 7% 20%No mat was formed, only a strand of polymer. Thickest fibres Research Findings HCI Conclusion: A keratin+PEO solution of concentration 10% is the optimal. Restriction of resources and time.

Research Findings AOS A solution was found that produced good fibres of elastin and keratin. The solution was 5%w of elastin and keratin, 5% w PEO and a very low concentration of sodium chloride. Different electrospinning Parameters including voltage and distance to the collector plate were varied to produce the best electrospun mesh from the initial solution. By varying the amount of moles of elastin and keratin in the initial solution, and electrospinning using the phase 2 variables, meshes with different ratios of elastin:keratin were electrospun Using SEM images and tensile testing results, it was discovered that a 1:4 ratio of elastin to keratin produced a material that was as extensible as spider silk, but not as strong.