A. B.

Topography Mechanisms and TopoGraft Evolution de

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- no strain mismatch needed - single material component or multiple materials possible - 3D printing fabrication - CAD files from proof-of-concept simulations (above) usable as initial product design inputs for printer - fast implementability - interchangeability of zero strain state because of 3D printing fabrication - curvature scaling set by kirigami geometry/thickness and tunable by kirigami spacing and attachement (parallel verus helical as shown by examples above with other patterns possible)- curvature actuation coupled to kirigami mechanics using Euler buckling

wrinkling topographyTopoGraft 1.1

kirigami topographyTopoGraft 3.0

corrugation topographyTopoGraft 1.2

↑P

3.1 non-helical 3.2 helical ballast topography

TopoGraft 2.0

↓P ↓P ↓P

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- composite material construction (membrane (Em)/substrate (Es) stiffness mismatch)- strain mismatch needed for actuation- proprietary fabrication method - curvature, wavelength, amplitude scaling well understood (see above exact calculated curvature scaling law that can be used to precisely tune anti-foulingfor a given foulant). - bio-mimetic design- prototype developed and fabrication process on-line- in-vitro data show great efficacy of technology, animal studies currently underway

zero strain state zero strain statezero membrane strain state

zero strain state zero strain state

- single component material (no membrane)- no strain mismatch needed, zero strain topographydirectly controlled by initial fabrication process - conventional fabrication methods including fiber extrusion - change in curvature during actuation (formulaabove) related to local amplitude and wavelength

- single or multiple material construction possible- no strain mismatch needed- void geometric parameters (spacing lb and thinness hb) couple with buckling to generate wavelength and amplitude - conventional fabrication methods possible (extrusion) - curvature actuation coupled to void mechanics using Euler buckling

TopoSystem Mechanism of Surface RenewalThe above different graft/surface geometries are all designed to generate a given surface curvature. The scaling of these curvatures with the applied and actuated global cylinder strainfield is different dependent on the design (see different scalings for curvature kappa above). Irrespective of how surface curvature is generated our theoretical work shows that fouling layers will de-adhere from a surface once the below criteria are satisfied thus driving surface renewal:

thin patch limit thick patch limit surface renewal criterium

C. D. E.