C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Main ideas: Use novel layered prototyping methods to create compliant biomimetic structures with embedded sensors and actuators (Cutkosky, Kenny, Full) Develop biomimetic actuation and control schemes that exploit “preflexes” and reflexes for robust locomotion and manipulation (Kazerooni, Howe, Shadmehr, Cutkosky)

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Building small robot legs with pre- fabricated components is difficult... Motor Leg links Shaft Shaft coupling Boadicea leg Electric motor/link

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Concept design for a biomimetic “Insect-Leg” A prototype design of the same leg employing three- dimensional plastic “exoskeleton” surrounding with embedded actuators, sensor and cooling system.

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Shape Deposition Manufacturing (SU/CMU)

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS SDM allows finished parts to be inserted at any point in the cycle Green link and red bearings are added as finished components

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS SDM capabilities Slides and web pages of parts that would be difficult or impossible to create using conventional manufacturing methods –Topology that would be almost impossible with conventional machining tilted frame (CMU/Stanford)tilted frame (CMU/Stanford) –Integrated assembly of polymers with embedded electronics and interconnects (CMU Frog Man)CMU Frog Man –other example parts from RPL at Stanfordother example parts from RPL at Stanford

MicroStructures and Sensors Lab (MSSL) Research on Fundamental Properties and Applications of MEMS-based MicroMechanical Devices. Micromechanical Sensors. Micromechanical Elements for Scientific and Technological Collaboration Partners. Devices and Instruments for Studies of Fundamental Properties of Micromechanical Structures. Collaborators : IBM, JPL, NRL, SNL, SAIC, Medtronic, Raychem, Lucas, Seagate, Perkin-Elmer... Students from :ME, EE, Appl Phys, A/A 2-Axis AFM Cantilevers for Surface Friction Experiments and Thermomechanical Data Storage Piezoresistive Lateral Accelerometer Flow Visualization in Microchannels Ultrathin Cantilevers for attoNewton Force Detection Kenny

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Epoxy acrylic Shape Memory Alloy wire with water cooling channels Embedded SMA actuators Intial experiments with epoxy and urethane polymers and various sacrificial support materials have underscored the need to build in disposable fixtures for proper alignment.

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Approaches to design with layered shape manufacturing Usually people think of taking a finished CAD model and submitting it for decomposition and manufacture Example: the slider-crank mechanism, an “integrated assembly” built by SDM

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS SDM process planning: geometric decomposition for tool access Cross section of part material (gray) in support material build direction

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS 11 Decomposition into ‘compacts” and layers Several levels of decomposition are required Complete Part CompactsLayersTool Path

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Testing for compactness There exists no point, p, on S which is an inflection point with an undercut surface above an upward-facing surface. Z

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Layers produced by automatic decomposer for slider crank mechanism Gray = steel, brown = copper support material

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Layered shape deposition - potential manufacturing problems finite thickness of support material poor finish on un-machined surfaces warping and internal stresses

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Slider crank can be built entirely from two kinds of primitives Yellow = part material, blue = support material

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Merge algorithm for compacts (Binnard) f (a,b )

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Truth tables for Boolean operations on compact lists P = part material S = support material c = f (a,b)

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Building Designs from Primitives Here is the result of building slider-crank from primitives allows manufacturability analysis at design time

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS SFF Object made up of Part and Support Compacts What gets sent to the Manufacturing Service Primitives + Merging Rules The Final Geometry What the Designer works with Building a robot joint from a library of shapes

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Link 1Link 2 Pneumatic Actuator Magnetic Gear Tooth Sensor Design for a prototype pneumatic knee joint built from primitives (M. Binnard)

C D R 5/17/ PI MEETING FOR LEGGED LOCOMOTION AND MUSCLE-LIKE ACTUATORS Decomposed Features SFF-MEMS VLSI Boxes, Circles, Polygons and Wires SFF-MEMS Design Rules Mead-Conway Design Rules   Wc/ >= 2 Minimum gap/rib thickness dd dd (top view)a) Generalized 3D gap/rib d  (side view)b) d  Minimum feature thickness d(m1,m2,m3) (side view)e) m1m2m3 d(m1,m2,m3,  ) m1m2m3 Comparison with VLSI approach