Biological Engineering
Topics to cover before the activities:
 The work that engineers do and the diversity of career opportunity within the
field
 Engineering design process (design, build, test)
 Biological Engineering programs at the University level and the high school
requirements needed
 Food Processing - Bacteria in foods (lactobacilli, the foundation of the dairy industry)
 Pharmaceuticals – Mad Cow sensor
 Prosthetics - hip implants
 Biomedical Applications - tissue engineering and regenerative medicine, imaging and xrays
Food Processing - Cultured Cream
Materials
 2 cups heavy cream
 measuring cup
 2 clean jars with lids
 cultured buttermilk
 sour cream
 spoons for stirring
 measuring spoons
* do not contaminate your experiment, keep materials clean and use different spoons for
each stirring operation
Procedure
1.
Put 1 cup heavy cream in each jar. Add 1 teaspoon cultured buttermilk to one jar and stir.
Add 1 teaspoon sour cream to the other jar and stir. Taste the contents of each jar.
2.
Screw the covers of the jars on tightly and put in a warm place overnight. The cream
should become too thick to pour (16 to 36 hours). The thickness of the cream is
considered the "measure of ripeness" of crème fraîche.
Follow-up
 Which is smoother? Which is more sour? (Different cultures give the cream different
flavors).
 Try with a yogurt culture: stir 1 teaspoon of plain yogurt into the heavy cream.
 Try with a yeast culture: mix 1/4 teaspoon active dry yeast with 1 tablespoon of warm
milk. Add to a cup of heavy cream.
 Test the effects of temperature on bacterial activity. Use a single starter culture and set up
three samples- fridge, heat, room temperature.
School of Engineering, University of Guelph
www.soe.uoguelph.ca
enginfo@uoguelph.ca
STAO November 2006 – Biological Engineering
Prosthetics - Hydraulic Arm
Materials
 cardboard
 scissors
 rubber bands
 tape
 string
 straws
Procedure
1. Trace and cut out a hand shape. Cut the fingers into three equal pieces.
2. Place the pieces back together and tape over the two finger joints, label this side “INSIDE”.
3. Cut a 5 cm piece of elastic. Turn the finger INSIDE face down. Place the elastic in the
middle of the first joint. Tape the elastic on either side of the joint leaving the ends of the
elastic un-taped. Bend the elastic back over the tape and tape again. (This helps prevent the
elastic from slipping).
4. Cut a 35 cm piece of string and tape one end firmly over the end of the finger.
5. Cut 3 pieces of straw into 2 cm for each finger. Thread the straw onto the string. Tape in the
middle of each of the finger sections on the “INSIDE”.
6. Operate your hand by pulling the strings and try picking up objects.
7. Roll newspaper for an arm. Tie loops in the end of the strings for your fingers. Attach the
hand to one end of the newspaper sleeve. Slide your arm in the other end and attach the
strings to your fingers.
“Outside”
“Inside”
Wrap-up
 What are some important requirements of prosthetic limbs
School of Engineering, University of Guelph
www.soe.uoguelph.ca
enginfo@uoguelph.ca
STAO November 2006 – Biological Engineering
Biomedical Applications – Surgical Tool
Materials
 8 popsicle sticks
 10 toothpicks
 drill with a small drill bit
 scissors
 plastic fork and spoon
 tape
Procedure
1. Drill holes into the popsicle sticks as indicated
by the circles in the diagram.
2. Lay the 4 pairs of popsicle sticks in the shape of
an ‘X’.
3. Tape a plastic spoon to the top of one of the
popsicle sticks and a fork to the other.
4. Connect each of the popsicle X’s by sticking the
toothpick through the holes created. Cut off the
excess on either end.
5. Hold onto the bottom ends and using a scissor
motion try out your surgical tool.
Follow-up
 Does it work better when there are more or less popsicle sticks used?
 Research some real surgical instruments and compare them to your design.
School of Engineering, University of Guelph
www.soe.uoguelph.ca
enginfo@uoguelph.ca
STAO November 2006 – Biological Engineering