Mechanics of Living, Squishy Materials

Transcription

1 University of Massachusetts Medical School UMass Center for Clinical and Translational Science Research Retreat 0 UMass Center for Clinical and Translational Science Research Retreat May 0th, :5 M - :45 M Mechanics of Living, Squishy Materials Alan Crosby University of Massachusetts - Amherst Follow this and additional works at: art of the Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons, Molecular and Cellular Neuroscience Commons, Nervous System Diseases Commons, and the Neurology Commons This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License. Crosby, Alan, "Mechanics of Living, Squishy Materials" (0). UMass Center for Clinical and Translational Science Research Retreat This material is brought to you by escholarship@umms. It has been accepted for inclusion in UMass Center for Clinical and Translational Science Research Retreat by an authorized administrator of escholarship@umms. For more information, please contact Lisa.almer@umassmed.edu.

2 Mechanics of Living, Squishy Materials Al Crosby olymer Science & Engineering University of Massachusetts Amherst

3 DISCLOSURE I have no actual or potential conflict of interest in relation to this program or presentation.

4 BioInspired Materials Mechanics BioInspired Adhesion and Friction Control Nanoparticle Stripes, Ribbons, and Ropes Snapping, Wrinkling, and Folding olymers Local Mechanics of Gels and Tissues

5 Tissue Mechanics Challenge: Understand the development of mechanical properties in soft networks across multiple length scales. Goal: Develop quantitative technique for synthetic and biological materials (in vitro and in vivo). Objective: Make measurement at arbitrary locations and on biologically relevant length scales ( m) Blood Brain Muscle Collagenous Bone fluid ka 0 ka 00 ka Most knowledge from extracted tissue What can we learn from studying tissues in their native state?

6 Inflation **Gent, A.N., Int. J. of Non-linear Mechanics 40 (005) o o r t G 7 o o r t G NeoHookean Hookean r o r t r inflation

7 Cavitation in Bulk 5 4 Gr o G **Gent, A.N., Int. J. of Non-linear Mechanics 40 (005) ro /G 3 d r o

8 Syringe Induced Cavitation E r dv da E s s E s

9 Cavitation Rheology Inner radius = 5 m Zimberlin et al. Soft Matter 007 Kundu and Crosby Soft Matter 009 Zimberlin and Crosby J. of oly. sci. part B 009 Zimberlin et al. Soft Matter 00 Crosby and McManus hysics Today 0 Cui, McManus, Crosby. Soft Matter, under review

10 Representative Data

11 Syringe Radius =.5 m

12 Dependence on Syringe Radius c 5 6 E r s

13 Size Dependence c 5 6 E r s E air =.4 ka air/gel = 0.07 J/m

14 Water Cavitation Zimberlin and Crosby, J. oly. Sci. hysics, 00. Inner radius = 7 m

15 Cavitation with Water

16 Surface Energy Effects c 5 6 E r s E air =.4 ka E water =.8 ka air/gel = 0.07 J/m water/gel = J/m **Zimberlin and Crosby, JS: B, 09, in press.

17 Deformation Transition olyacrylamide (AAm); monomer amount varied to obtain gels with different polymer volume fraction (). **Kundu and Crosby, Soft Matter, 009, 5,

18 Reversibility < 0.03 > 0.03 c ~ E r s E cavitation : 400 a E contact mech : 500 a c E r s

19 Size Dependence c Cavitation 5 ~ E 6 r s c Fracture G r c s E

20 E: Volume Fraction Scaling E 3kT b 3 N N f 4 3 3kT E 3 b.3 **Kundu and Crosby, Soft Matter, 009, 5,

21 G c : Volume Fraction Scaling G c NU chains area *Lake and Thomas, roc. Royal Society: A, 967. chains area N b **Obhukov, Rubenstein, Colby. Macro G c U b 5 4 **Kundu and Crosby, Soft Matter, 009, 5,

22 Cavitation to Fracture Transition.3 3 s s f c r b U kt kt b b r U kt **Kundu and Crosby, Soft Matter, 009, 5,

23 The Vitreous Humor Weak gel that is 99.9% water and dissolved salts Held together by vitrosin fibers and hyaluronic acid Very fine network of fibrils D ~ 0-5 nm Bos, et. al., Micron 3 (00) M M Le Goff and N Bishop, Eye (9 Feb 008), doi: 0.038/eye.008., Review

24 Time Effect on in vitro Vitreous Modulus decrease with time of vitreous solution Attributed to hyaluronan loss in the exuded aqueous Journal of Biomechanics 4 (008)

25 Vitreous Cavitation erformed cavitation rheology on bovine eyes Two conditions: Vitreous in eye Vitreous removed Demonstrates ability to perform in vivo mechanical characterization rovides insight design of biological networks Zimberlin, J.A., et. al. Soft Matter, 00.

26 Eye Data Sample E (a) CR in Eye 600 CR extracted 99 Kornfield** 60 Consistent with predictions that internal network tension contributes to stiffness Zimberlin, J.A., et. al. Soft Matter, 00. **Journal of Biomechanics 4 (008)

27 The Lens Chemical composition 35w% protein 90w% are water-soluble proteins (crystallins), including α, β h, β l, γ.

28 Critical ressure Cui, McManus, Crosby. Soft Matter, under review, 0.

29 In collaboration with rofs. Jennifer McManus and Sean Commins at NUI Maynooth, Ireland Mapping Brain Tissue in vivo

30 Summary Biological systems provide many lessons, key points can be hidden Elastic instabilities offer advantages for material characterization Cavitation provides unique exploration of length scale and deformation properties of 3-D networks

31 Funding: NSF DMR ARO DARA - Draper Labs NSF MRSEC at UMass NSF NSEC at UMass DOE EFRC at UMass NSF IRE program NSF IGERT on Nanotechnology Collaborator: Graduate Students Derek Breid Chelsea Davis Hyun Suk Kim Yuri Ebata Jun Cui Sam endergraph Michael Bartlett Yujie Liu Marcos Reyes-Martinez Dan King Yu-Cheng Chen Jon ham ostdoctoral Researchers Dinesh Chandra Dong Yun Lee Aline Delbos Undergraduate Researchers rateek Katti Jacob Labelle Beth aret Rola Hassoun Matt Leonard Jennifer McMannus (NUI Maynooth, Ireland)

32 The Group