Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Building small robot legs with pre- fabricated components is difficult... Motor Leg links Shaft Shaft coupling Boadicea leg Electric motor/link

IV. Fabrication and integration experiments 2:00-2:30pm (*Cutkosky, Kenny, Howe) Overview of SDM fabrication process, capabilities, challenges Autonomous robots: experiments with UCB, SRI, (others?) Cooperative robots: experiments with Harvard, Johns Hopkins, UCB

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA 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.

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Mechanics and muscle activation patterns (R. Full) Three-dimensional musculo-skeletal model of the leg of B. discoidalis constructed by Full’s lab. Simulations such as these help characterize the role of individual muscles in locomotion.

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Shape Deposition Manufacturing (SU/CMU)

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA SDM allows finished parts to be inserted at any point in the cycle Green link and red bearings are added as finished components

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA 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

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Frogman (CMU) Example of polymer component with embedded electronics using shape deposition manufacturing

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

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA 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.

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Embedded sensor example : pressure sensor unit for pneumatic actuators Screen shot from SDM CAD environment: several steps in the “building block” design/fabrication sequence for the embedded pressure sensor package PC board CAD file for commercial MEMS pressure transducer & instrumentation

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Embedded sensor example (continued) Completed pressure sensor unit ready for connection to a pneumatic actuator. A batch of four parts during the final machining step. Part material is urethane (yellow). Sacrificial support material is wax (red), filling cavities and encasing the circuit leads to protect them. Fabrication instructions archived at

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA 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

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA SDM process planning: geometric decomposition for tool access Cross section of part material (gray) in support material build direction

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA 15 Decomposition into ‘compacts” and layers Several levels of decomposition are required Complete Part CompactsLayersTool Path

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA 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

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Layers produced by automatic decomposer for slider crank mechanism Gray = steel, brown = copper support material

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Layered shape deposition - potential manufacturing problems finite thickness of support material poor finish on un-machined surfaces warping and internal stresses

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Slider crank can be built entirely from two kinds of primitives Yellow = part material, blue = support material

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Merge algorithm for compacts (Binnard) f (a,b )

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Building Designs from Primitives Here is the result of building slider-crank from primitives allows manufacturability analysis at design time

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA 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

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA Link 1Link 2 Pneumatic Actuator Magnetic Gear Tooth Sensor Design for a prototype pneumatic knee joint built from primitives (M. Binnard)

Fabrication 9/6/98 Sept 9-10, 1998 MURI Kick-off meetings, Berkeley/Stanford, CA 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