G6 Centrifuge Activity - STEAM for students

Steam engineering

1. Centrifugation

2. To demonstrate the application of centrifugal forces. To experiment separating components of a solution that are too light to be separated by sedimentation.  To design and build a centrifuge and test its working. Learning Objectives

3. Can you explain why this is happening?

4. Centrifugation  is a technique used for the separation of particles from a solution according to their size, shape, density, the viscosity of the medium and rotor speed. The particles are suspended in a liquid medium and placed in a  centrifuge tube . The tube is then placed in a  rotor  and spun at a defined speed. Rotation of the rotor about a central axis generates a  centrifugal force  upon the particles in the suspension. In centrifugation, we use the force exerted by rotational motion in order to separate out components of a mixture that have different weights. This is very useful in separating components of a solution that are too light to be separated by sedimentation.  Centrifugation

5. Overview: Students will design and build a Lego centrifuge and test if their model can separate simple insoluble solution. Helpful Facts: The application of such a device is to separate plasma, white blood, and red blood cells. Mixtures inside the test pipes will experience great horizontal centripetal force (multiple of g) and thus reduces the time required for precipitation. Activity – Design and build a Centrifuge

6. CENTRIFUGE Building instructions

7. Once the design and the prototype are ready, the students will make samples of chalk with water and sand with water in separate test tubes. They will insert the test tubes in the centrifuge and run the motors at full speed. After 1 minute, they will stop the motors and will observe the samples. They will observe the insoluble solute stay at the bottom of the test tubes. They can compare the samples before and after centrifugation. Contd.

8. Challenge

9. Challenge Try to design and make a working model of the hand spinner and test different miscible substances and separate them.