Make your own Grabber Arm!

Got something that's just out or reach? Now you can make a grabber arm that can help you retrieve things!

Materials:

• 8 craft sticks
• 2 milkshake straws, cut into quarters
• 2 skewers
• Tape

Optional:

• Pipe cleaners
• Rubber bands
• 2 cups

Procedure:

1. Create the four beams by sticking a craft stick into the straw pieces are each end leaving a small gap in the straw between the two craft sticks.

2. Break off a small piece of skewer and tape it at the edge of each straw piece in order to help reinforce them.

3. Attach two of the beams together by sticking the pointed end of the skewer into the straw pieces in the beams. Do this for both pairs of beams.

4. Put more straw pieces on the end of the one side of the "X" created by the attached beams for both sets.

5. Line up the upper and lower parts of the beam so that the newly attached straws overlap and stick a skewer piece though the straw pieces. Use tape and skewer pieces to reinforce as necessary.

6. Design the grabber claw. This can be more pieces of crafts stick, bent pipe cleaners, rubber bands or anything else you can think of that will help you pick up an item.

7. Test your grabber by trying to pick up the cups.

Engineering involved: This grabber is a simple machine that serves to show the importance of design. While the basics remain the same, this grabber can be customized to pick up different types of objects with different types of claws. Just like any good machinery, it can be redesigned for the optimal effect, whether it needs to be able to hook into something or have a better grip using the rubber bands. And just like a real engineer, it's up to you to experiment and figure out the best way of completing a task. Good luck and happy testing!

For more pictures and information go to: http://www.instructables.com/id/Extending-Grabber/?ALLSTEPS

Gumdrop Structure Challenge!

The challenge: Using only 20 toothpicks and 10 gumdrops, design a structure that can support the weight of a textbook.

Materials needed:
-20 toothpicks
-10 gumdrops
-newspaper or something to keep table surface clean

Further challenges (optional):
-A time limit
-A minimum height the textbook needs to be off the table

The Science:
Hopefully, after completing the challenge, you can see several scientific and engineering connections to this activity. First of all, we can see that triangles are STRONG. This is why many bridges around the world are made out of triangles. Next, we also learned that larger bases mean more support and therefore, the structure can hold more weight.

Invisible Ink!!!

Ever want to create a top secret message??? Well now you can! And you can use science to do it!

Enjoying using chemistry and the following readily available kitchen items to send secret messages to your buddies!

Here's what you need to get started:
baking soda
paper
water
paint brush (or you can use your finger)
measuring cup
purple grape juice concentrate


Directions:
Mix water and baking soda in a bowl in equal quantities. Be sure to use your measuring cup here.

Then use a paint brush or your finger to paint on your top secret message to paper.
Note: you won't be able to see what you are writing! That's what makes it top secret!

Allow message to dry.

Next, to have your secret messaged reveled paint over you message with grape juice.

YOUR MESSAGE WILL MAGICALLY APPEAR!

Well, not exactly magically... 

Here is what happened:

The baking soda and water mixture you used to paint on your message constitutes a weak base.  Weak bases have high pH values and do not ionize fully.  Grape juice is an acid.  The message is written in a weak base, and this weak base neutralizes the acid in the grape juice, therefore, revealing your message! 

Enjoy sending secret messages!