Alan W. Eberhardt, 1 R. Justin Lesley 1 Tina G. Oliver, 2 Rose N. Scripa 3 Biomedical Engineering, 1 Mechanical Engineering, 2 Material Science & Engineering 3 University of Alabama at Birmingham Birmingham, AL Appropriate Technology in an Introductory Engineering Design Experience

Outline Undergraduate Designs to Aid Disabled NSF & NCIIA activities SIFAT, Engineers w/o Borders & Zambia EGR 200 design project Appropriate technology constraints Engineering design tools Assessments and Results student & faculty perspectives

NSF RAPD funding 13 years + Projects to aid children & adults (in Alabama) with various disabilities Senior Design EGR 100, 200 BME, MSE, ME Undergraduate Design Projects for People with Disabilities

New direction: Appropriate technologies NCIIA funding – 2 years Partner with EWB using appropriate technologies Senior design projects for disabled in developing countries Peru – all terrain crutch Zambia – bamboo wheelchair

UAB Engineers w/o Borders + SIFAT (Servants in Faith and Technology) SIFAT: Christian nonprofit that provides training in self- help programs for a needy world. EWB + SIFAT building a training facility in Zambia Opportunity for reproduction of devices designed by UAB students

EGR 200 Intro to Engineering Course is for 2 nd year transfer students (pre-BME, -ME, -CE etc) Majority from 2-year community colleges 2 sections of ~50 students Topics: Reverse engineering, team projects, oral & written communication + 5 week design project

Design Project: Crutches using appropriate technology Crutches for men, women and children of Zambia Zambia One of the poorest countries in the world 87% of total population live on less than $2 USD per day Health problems abound… Ex. Infection leads to amputation… war torn neighbors

Design Constraints Appropriate materials Bamboo poles, string, glue, leather, cloth scraps, burlap Appropriate technology Hand tools only (saws, files, vises, hand drill) No power tools or expensive machining equipment Time: 5 weeks (end of term)

Schedule – Fall 2010 ClassDateActivity 110/29Introduction to problem 211/5Lab Safety, SOE Design Lab visit, Brainstorm designs 311/12Project work* – materials list due by end of class 411/19Project work* - continued X11/26Thanksgiving holiday 512/3Project work*, stress analysis 612/10Oral presentations/reports & completed crutches due * class time to work in teams SOE Design Lab/computer labs

Design Contest Crutch designs judged for Best Engineered Device based on Final Presentation + Final Report Winning team gets dinner at Dreamland Bar-B-Q Best engineered based on use of engineering tools in design Computer aided drawing Free body diagrams, force/moment calcs Stress and buckling analysis Material description – engineering properties

Drawing Discuss the range from hand sketching to Pro-E CAD Intro to Pro-E demo, some students taking Pro-E course

Statics, Equilibrium & FBDs F = 0 Action-reaction (Newtons 3rd) M = 0 Ex. Civil War era crutch 1. Underarm piece P P P M

Mechanics of Solids aka, Stress and Strain Fundamental concepts of stress and strain can be illustrated by considering a prismatic bar (straight structural member with constant cross section) that is loaded by axial forces P at the ends Material failure is often a function of stress or strain (not just the force applied)

Stress - strain curve: Engineering materials In elastic zone, = E Hookes Law

Material selection/analysis CES Edupak software On EGR computers: Programs Engineering software CES Properties of bamboo Modulus Failure strength Joining techniques

Column Buckling P crit = 2 EI/L e 2 Note: The effective length L e depends on the boundary conditions

Important! Allocated class time for project work SOE Design Lab Tables for teams with materials (bamboo, string, glue, etc) Hand saws/drills, files… Instructor + grad student (Lesley) circulating & advising…

Rubric circulated Students told how they would be graded = how judged for contest….

Results & student learning outcomes: All design teams completed their projects (19) Student ownership & satisfaction was remarkable (personal best for freshman experience) Students comments: understand what it means to design … what engineers do… feel prepared & excited for next level courses… Many signed up for UAB Engineers w/o Borders

Benefits from the teaching end Costs are low $500 covered two sections of ~50 students Materials purchased a priori & provided Bamboo, string, glue, leather, burlap Facilities are simple Hand tools (saws, files, hand drills, vises) Projects are safe No special training needed…

Acknowledgments National Science Foundation (NSF RAPD) National Collegiate Inventors and Innovators Alliance (NCIIA) UAB School of Engineering Dreamland BBQ Thank you!