Bio Inspired Design - Lecture10. Biomotion bioclamping_part1

Wb2436-05, Paul Breedveld, Bioclamping

Bio-Inspired DesignWb2436-05

Paul Breedveld

Lecture 10

Bioclamping

TechnicalCounterpart

Large numberof examples

BiologicalClamping Method

Adhesion

Suction

Grasping

Overview

Electro-Magnetism

Freezing & Melting

…

No biologicalcounterparts

(?)


Grasping AdhesionSuction



(2 dimensional case → 2 contact points)

Case 1: Two rigid surfaces• Grip stays equal when surface area changes• Grip can be increased by increasing • normal force & friction coefficient


Increasing grip byincreasing friction coefficient …


FNFfric


Fpull


Case 2: One or two deformable surface(s)• Friction much larger because of• increased contact surface• Normal forces in different directions can• help to increase grip• Friction not necessary for achieving grip!Wb2436-05, Paul Breedveld, Bioclamping

Increasing grip byvarying the direction of the normal forces …

FN



Fpull



Fpull

FN, res

Increasing grip byvarying the direction of the normal forces …

Atraumatic?

Surgical Forceps



Ripples increase frictionWhy are they circular?

Grip increases perpendicular to rippleGrip increases in all directions!



Puffin(Papegaaiduiker)





Friction notnecessary to achieve grip!(normal forces~parallel to pulling forces)

IntestineInspection DevicePaolo Dario, PisaSpikes





Case 3: Shaping around an object• Normal forces in direction you want• Strong increase of grip• Role of friction less and less

FN



Increasing grip byshaping around an object …

Curved Forceps & Hooks



A hole can also serve as Shape Grip…



Knot

BiologicalHelicalTensionSpring!



Shape GripperHirose & Fukushima lab.

Tokyo Institute of Technology





SARAH robothandRobotics Laboratory, Laval University, Canada



Summary: How to increase grip when grasping?

Passive: • By increasing the friction coefficient (rubber, etc.)• By varying the direction of normal forces • (teeth, ripples, spikes, etc.)• Only in case of deformable contact surface(s)!

Active:• By shaping around an object



Summary: How to increase grip when grasping?

Passive: • By increasing the friction coefficient (rubber, etc.)• By varying the direction of normal forces • (teeth, ripples, spikes, etc.)• Only in case of flexible contact surface(s)!

Active:• By shaping around an object

Friction can in these case be zero while still having sufficient grip

Sucking Cup



Why many small suckersinstead of a few big ones?



High stresses in tissueRisk of tissue damage

& losing grip



Low stresses in tissue



Leakage stops suction




Suction continueswith multiple suckers




Octopus heart stabilizer for bypass surgery



Wall-climbing robotShigeo Hirose, Tokyo


no air flowvalve open

air flowvalve closed



Dry adhesion(Gecko)



Gecko Setae



Spider SetaeWb2436-05, Paul Breedveld, Bioclamping


Spider Setae

0.5μm


2 rigid objects: Only few contact points

Friction independent of contact area




1 (or 2) very flexible objects: Large number of contact points

Friction strongly depending on contact area

Setae behave like flexible leaf springsPads are pushed against the surface

Molecular contact van der Waals forces




Thick supporting “leaf springs” for larger adaptability at more strength



Multiple leaf spring construction in wiper blade(ruitenwisser)


2μm Artificial SetaeDry tape?




StickyBotStanford University

Biomimetics & Dexterous Manipulation Laboratory

Gecko-likeGlass climbing robot

• No setae, no v/d Waals• Toes covered with• flexible, flat, sticky surface



SpinyBotStanford University

Biomimetics & Dexterous Manipulation Laboratory

Gecko-likeConcrete climbing robot

• No setae, no v/d Waals• Toes covered with many• leaf-springs ending in• sharp curved hooks


How to lift a foot that sticks?



How to lift a foot that sticks?

Unrolling!Lifting the 2-D surface impossibleLifting the 1-D borderline easy


Bio Inspired Design - Lecture10. Biomotion bioclamping_part1

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Transcript of Bio Inspired Design - Lecture10. Biomotion bioclamping_part1