B IOMIMETRIC C RAB Bill Dwyer Joe Mead Shaynae Moore Casey O’Connell WEEK 3

Pinching motion needs to be quicker than flexion and extension motion. We are modeling the Blue Crab Pneumatically powered 3 muscles per claw Running of RIT house air Design for 40 psi (60 psi upper limit.) Aquarium will be provided and sized according to our size requirements. Low risk for exploding surgical tubing. High cyclical repeatability Governing equations for McKibben muscles. BRAINSTORMING: P ROJECT KNOWN ' S ( UPDATE )

BRAINSTORMING: P ROJECT U NKNOWNS (U PDATE ) What materials will the crab be made out of? How will the crab be encased? Will our device move through locomotion? What will the length of our muscles be? How will the crab be designed so it will remain flush on the aquarium floor Will there be a cabin that will house the muscles or will they be located on the underbelly of our device? How will the range of motion intervals be incorporated Example (antagonistic muscle pairs?) Blue Crab Species information and movement. How rigid/buoyant will the umbilical chord become after pressurizing.

E NGINEERING S PECIFICATIONS ( S EE S PREAD S HEET )

P ROJECT R ISKS ( S EE S PREAD S HEET )

C ONCEPT D EVELOPMENT Preliminary Biomimetic Crab design Pincher Claw Wrist NOTE: This is underside of assembly to hide Mechanics. The Left and right assemblies are mirror copies. Both assemblies will function simultaneously and individually.

C ONCEPT D EVELOPMENT The spring creates force required to open the pincher and keep it in the rest phase. The McKibben muscles creates the force required to close pincher

C ONCEPT D EVELOPMENT The Pincher control line passes directly over the wrist joint to minimize deflection in wrist articulation The spring provides force that keeps wrist at neutral or zero angle of rotation The wrist is operated by two McKibben muscles to create positive and negative rotation

C ONCEPT D EVELOPMENT Frame or Platform Design Simply flat plate design for easy mount of; Arm Assemblies Legs Assemblies McKibben muscles Aesthetic cover plates

C ONCEPT D EVELOPMENT Aesthetic Covering Cast fiberglass, foam or gel pieces Rubber “suit” the frame fit inside Worst case paint entire Crab