Manotech Associates Low-Cost Prosthetic Hand February 9, 2006 Jina Kim Forrest Liau David Lin Kelsey Vandermeulen Teresa Wang

Motivation In low-income communities, hands important Accidents and civil war --> amputation Cosmetics highly valued Functional body important for status in society

Current Solutions Purely cosmetic Functional Complex system R. Doshi, Stanford University

How Can We Help? Novel mechanical design  Not our expertise Much prior art exists Underlayer material  Skin  Fingernail  Focus on one or more of these

Area of Innovation Customizable aesthetics Underlayer Size Shape Skin Color Texture Fingernail Size/shape/color/texture

Concepts for Size/Shape Customization Do-it-yourself custom mold Inexpensive factory-made mold sets Adjustable mold (?)

Concepts for Color Customization Heat treatment Chemical treatment Paint/spray/coat

Concepts for Texture Customization Heat treatment Chemical treatment Abrasion Printing Manual application

Work Plan Overview Determine specs and desired properties Research materials Test materials Assess feasibility of concepts Prototype prosthetic hand Test prototype

General Schedule Design ReviewMid-term Review Final PresentationInitial Prototype

Questions? Manotech Associates Forrest Liau -- David Lin --

Backup Slides

Underlayer Engineering Desired Material Properties Durable and lightweight Shapeable for easier processing Process Option 1: Use a relative’s hand for customization Requires low-cost, quick-drying material Option 2: Use CAD and 3D printing to create different-sized molds More flexibility in selecting the mold material

Skin Engineering Desired Material Properties Liquid, spray, or thin films Possibly disposable High melting temperature Waterproof, elastic Bonds well (chemically, preferably) to underlayer Process Liquid “skin”: Dip underlayer into liquid and allow it to dry Paint underlayer Spray: “Spray-on” skin Consumer-friendly, convenient

Prosthetic Production Considerations Color: prosthetic matches natural skin tone Shape: depends on user’s age and size Texture: to allow for gripping Product Option 1: underlayer only Simpler processing Product Option 2: underlayer + skin Skin can be replaced, instead of entire prosthetic Less concern about underlayer appearance, allowing for greater range of material options

Testing Durability Expose prototype to heat and water Material contact with environment (dirt, animal hair, crops) Determine time frame of wearing out Social acceptance Survey prototype “authenticity” in affected populations