Department of Mechanical Engineering THE STRUCTURE AND MECHANICAL PERFORMANCE OF TELEOST FISH SKIN by Lawrence J. Szewciw Department of Mechanical Engineering, McGill University, Montreal March, 2015 A Thesis Submitted to McGill University In partial fulfilment of the requirements of the degree of Doctor of Philosophy, Mechanical Engineering © Lawrence J. Szewciw, 2015 TABLE OF CONTENTS LIST OF FIGURES .................................................................................................................. VII ABSTRACT ............................................................................................................................... XII ACKNOWLEDGEMENTS .................................................................................................... XIV PREFACE & CONTRIBUTION OF AUTHORS ................................................................ XVI CHAPTER 1: INTRODUCTION .............................................................................................. 19 1.1. Infraclass Teleostei & the biomimetics of teleost fish skin ................................... 20 1.2. Applications to fish skin-inspired biomimetic materials ...................................... 27 1.3. Thesis objectives ....................................................................................................... 30 CHAPTER 2: THE STRUCTURE OF STRIPED BASS FISH SKIN .................................. 31 2.1. Overview: The hierarchical structure of teleost fish skin .................................... 32 2.2. Individual scales ....................................................................................................... 35 2.3. Arrangement of scales (scalation pattern) ............................................................. 41 2.4. Stratum compactum ................................................................................................ 42 2.4.1. Material & methods .................................................................................. 43 2.4.1.1. Sample collection & dissection .................................................. 43 2.4.1.2. Histological processing & microscopy ...................................... 44 2.4.1.3. Image analysis ............................................................................. 45 2.4.2. Results ........................................................................................................ 46 2.4.2.1. Collagen fibre & crimp angles................................................... 46 II CHAPTER 3: TENSILE PROPERTIES OF STRIPED BASS FISH SKIN ......................... 48 3.1. Overview: The tensile properties of teleost fish skin ............................................ 49 3.2. Tensile tests on individual scales ............................................................................ 51 3.2.1. Material & methods .................................................................................. 51 3.2.2. Results ........................................................................................................ 53 3.3. Tensile tests on stratum compactum ...................................................................... 56 3.3.1. Material & methods .................................................................................. 56 3.3.1.1. Dissection & specimen collection .............................................. 56 3.3.1.2. Specimen preparation & test procedure .................................. 57 3.3.1.3. Data analysis (tensile property calculations) ........................... 59 3.3.2. Results ........................................................................................................ 60 3.3.2.1. Stress-strain curves for parallel specimens .............................. 60 3.3.2.2. Tensile properties vs. location correlations .............................. 61 3.3.2.3. Tensile property maps ................................................................ 62 3.3.2.4. Stress-strain curves for perpendicular specimens ................... 63 3.4. Discussion.................................................................................................................. 64 CHAPTER 4: PUNCTURE PROPERTIES OF STRIPED BASS FISH SKIN .................... 68 4.1. Overview: The puncture resistance of teleost fish skin ........................................ 69 4.2. Puncture tests on individual scales ......................................................................... 71 4.2.1. Material & methods .................................................................................. 71 4.2.1.1. Analytical “four flaps” model.................................................... 72 4.2.2. Results ........................................................................................................ 76 4.3. Puncture tests on groups of scales .......................................................................... 79 III 4.3.1. Material & methods .................................................................................. 79 4.3.1.1. The puncture performance of striped bass fish skin ............... 79 4.3.1.2. Effect of substrate stiffness ........................................................ 79 4.3.1.3. Effect of puncture site ................................................................ 82 4.3.1.4. Effect of number of overlapping scales .................................... 83 4.3.1.5. Effect of friction between scales ................................................ 83 4.3.1.6. Effect of scale arrangement ....................................................... 85 4.3.1.7. Effect of scale interaction & force dispersal ............................ 87 4.3.2. Results ........................................................................................................ 88 4.3.2.1. The puncture performance of striped bass fish skin ............... 88 4.3.2.2. Effect of substrate stiffness ........................................................ 89 4.3.2.3. Effect of puncture site ................................................................ 90 4.3.2.4. Effect of number of overlapping scales .................................... 92 4.3.2.5. Effect of friction between scales ................................................ 94 4.3.2.6. Effect of scale arrangement ....................................................... 95 4.3.2.7. Effect of scale interaction & force dispersal ............................ 96 4.4. Puncture tests on stratum compactum .................................................................. 98 4.4.1. Results ........................................................................................................ 98 4.5. Discussion.................................................................................................................. 99 CHAPTER 5: FLEXURAL PROPERTIES OF WHOLE STRIPED BASS FISH ............ 105 5.1. Overview: The bending properties of whole teleost fish .................................... 106 5.2. Whole fish bending tests (scaled vs. descaled) ..................................................... 110 5.2.1. Material & methods ................................................................................ 110 IV 5.2.1.1. Sample collection & dissection ................................................ 110 5.2.1.2. Test procedure .......................................................................... 112 5.2.1.3. Image analysis (coordinate selection) ..................................... 113 5.2.1.4. Data analysis (curvature & moment calculations) ................ 114 5.2.2. Results ...................................................................................................... 117 5.2.2.1. Bending moment vs. curvature at three locations ................. 117 5.2.2.2. Bending moment vs. curvature vs. curvilinear distance ....... 118 5.3. Whole fish bending tests (descaled vs. incised) ................................................... 119 5.3.1. Material & methods ................................................................................ 119 5.3.1.1. Sample collection & dissection ................................................ 119 5.3.1.2. Test procedure .......................................................................... 119 5.3.1.3. Image analysis (coordinate selection) ..................................... 120 5.3.1.4. Data analysis (curvature & moment calculations) ................ 120 5.3.2. Results ...................................................................................................... 120 5.3.2.1. Bending moment vs. curvature at three locations ................. 120 5.4. Striped bass body morphometrics ........................................................................ 121 5.4.1. Material & methods ................................................................................ 121 5.4.2. Results ...................................................................................................... 122 5.5. Discussion................................................................................................................ 123 CHAPTER 6: GENERAL DISCUSSION & FUTURE WORK .......................................... 128 6.1. Thesis contributions ............................................................................................... 129 6.2. Biomimetic design of protective systems inspired from fish skin ...................... 134 V REFERENCES .......................................................................................................................... 141 VI LIST OF FIGURES Figure 2.1.