As an introduction to bioengineering, students design and build a prototype of an artificial limb using a simple syringe system. Students determine which substance, water (liquid) or air (gas), makes the appendage more efficient.

Bioengineering technologies explore the production of mechanical devices, products, biological substances and organisms to improve health and/or contribute improvement to our daily lives. air artificial limb assistive technology blueprint bioengineering gas liquid prototype sub-system system water Students should have prior experience with, or an introduction to the following concepts: hydraulics, joints, muscles, tendons, ligaments, bones, states of matter. Describe how movements of bones are dependent upon the interaction of pairs of muscles. Identify the major bones and muscles of the arm and leg. Explain that a force (push or pull) is needed for movement. Explain that movement is a complex process involving more than one body system. List all body systems involved in movement. Describe how the location of muscle attachment is important to the movement of the bone. List and describe the working of different joints. 14-10 ml oral syringes 7-30 cm length pieces of ¼-inch aquarium tubing 20 Popsicle sticks 5 rubber bands 1 meter of duct tape string water NASA is currently working on setting up a workstation on the moon. You are part of a team that has just landed there. One of your team members has an artificial arm and leg and has lost functionality of his limbs. It is up to your team to design and build one of the replacements. The only materials at your disposal are: Popsicle sticks, string, duct tape, water and aquarium tubing and these materials must be shipped from the main shuttle located above the moon to the station where your team is located. To connect with a joint. Rigid connective tissue that makes up the skeleton of vertebrates. The process of pressing items together. To draw or squeeze together so as to make or become smaller or shorter and broader. To break open or through. A phase of matter in which the molecules are widely separated, move around freely, and move at high speeds. A tough band of tissue that holds bones together or keeps an organ in place in the body. A phase of matter that is free to conform to a shape of a vessel, but has a fixed volume and has a greater density than a gas. A body tissue consisting of long cells that can contract and produce motion. A unit of force that is of such size that under its influence a body whose mass is one kilogram would experience an acceleration of one meter per second per second. To make or become loose or less tense. A phase of matter characterized by resistance to deformation and changes of volume. A group of objects or units combined to form a whole and to move or work together. A tough cord or band of dense white connective tissue that links a muscle to some other part. Direct the group todesign a robotic arm or leg that simulates the body movement of that part. The design should include a sketch with all parts labeled. For example: Popsicle sticks representing bones and the bone labeled (humerus). Please refer to the design sketch rubric. Decide how many syringes, Popsicle sticks, rubber bands and length of duct tape and/or string the team needs. Fill out the materials request form and submit it to obtain materials. Build a prototype of the device. Test and evaluate the design based on the provided rubric. Have each group share their design with the class and demonstrate how it works in relation to movements and parts of the body. Remember to use appropriate terminology. Put together two syringe sub-systems. Define a sub-system as a piece of tubing with a syringe attached at each end. See Figure 1. Fill one sub-system with water. Do this by removing both plungers from the syringes. Now place the open end of the syringe side A under a water faucet while holding syringe B at a lower elevation. Fill the sub-system with water until it overflows. Turn water off. Holding both syringes A and B at an equal elevation, place plunger A into syringe A and push plunger SLOWLY all the way down. Water will enter syringe B, filling it completely. Finally, place plunger B into syringe B. Make sure that the plunger is in contact with water and not air. If necessary, top off syringe B with water. This is a hydraulic sub-system because it contains a liquid. The other sub-system is filled with air (gas) and it is called a pneumatic sub-system. Hydraulic Sketch Rubric (doc) Hydraulic Sketch Rubric (pdf) Hydraulic Test and Evaluation Sheet (doc) Hydraulic Test and Evaluation Sheet (pdf) Hydraulic Robots 101 (doc) Hydraulic Robots 101 (pdf) Student Worksheet: Device Procedure (doc) Student Worksheet: Device Procedure (pdf) Student Worksheet: Fluid Capacity (doc) Student Worksheet: Fluid Capacity (pdf) Beware of a rubber band flying out of control or a Popsicle stick making an unscheduled detour across the room. Students may have difficulty filling up the tubing and syringes with water. Make sure no air is in the line. Students' arm or leg prototypes may buckle. If this happens, direct students to look at the placement of the rubber band and adjust it. Have students draw diagrams of arms and/or legs. Have them indicate the locations of muscles, ligaments and tendons, and explain how they work. Have students keep journals of their daily accomplishments. Evaluate students' ability to present and explain how the arm/leg works using the appropriate terminology, as it relates to the rubric. NASA has accepted your design and wants to have several devices on hand to avoid any further delays in the future. Based on the material used by your team, create a list of materials, amounts used, and prices for a single device. Now compute the cost for 5, 10, 25 and 100 devices. Your material supplier will reduce your cost by 15% if you make 100 devices. How much can you save with this 15% discount? 15-10 ml oral syringes 8-30 cm length pieces of 1/4-inch aquarium tubing 6 Popsicles sticks 5 rubber bands 1 meter of duct tape Student Worksheet: Mass Production Cost (doc) Student Worksheet: Mass Production Cost (pdf)