In the Robot Test Kitchen, we talk about five main barriers that we typically face in conducting technology programming in our libraries: time, budget, skill, interest, and support. It’s our belief that most of these are not impossible barriers, but sometimes it’s hard to see how. Especially when things like your time and budget are already stretched paper thin.

On Tuesdays, we’re tackling the budget question with programs you can run at your library for under $10. We’re also addressing the interest and support questions by asking you to share your inexpensive STEM programs in the comments, and to let us know what kinds of feedback you’ve gotten when you’ve tried these or similar programs in your buildings! This week: Build a Better Speaker

One of our inspirations in the Robot Test Kitchen is another ILEAD team, the librarians behind Make It At Your Library. Their site, partnered with Instructables, has a wealth of ideas and ready-to-go programing fodder. Today, I’m highlighting something I found on their site and is an ideal match for a technology exploration club, a musical themed summer reading or Teen Read Week program, or just a one-off teen or tween program.

As you can see from the image above, this is a simple project: paper towel tubes, paper cups, and a craft knife or scissors are all you’ll need to do it. The RTK spin here is in challenging your teens to improve upon this basic design to yield the best results possible. Assemble your supplies based on the questions you’re going to ask. Some suggested questions are…

• What happens if you use plastic cups instead of paper? What about styrofoam?
• How long should the paper tube be for the best sound?
• At what volume should the iPod or phone be set to hit that sweet spot between distortion and amplification?
• Does lining the tube with tin foil make a difference?
• Where in the room should the speaker be placed? How high? On what kind of surface?
• Does changing the shape of the tube or the direction of the cups make a difference?

Once your participants have created their best version, have a proving ground. Test the sound on each speaker with the same song set at the same volume, and use another device to measure the decibels.

Age:

tween – teen (watch the young ones with the craft knives though)

Cost:

$0 – $10 (assuming you have access to at least two smartphones or mp3 playing devices)

Supplies:

• A variety of disposable cups
• Paper towel and toilet paper tubes (plan ahead and collect from staff!)
• sharp scissor or craft knives
• foil
• tape
• other craft supplies you have on hand to embellish or improve the speaker

Time:

Give yourself a couple hours prep time to make some demos and gather all of your supplies. Add some extra time if you need to hit the grocery store for additional materials. Running the program itself can be done in under an hour.

In the Robot Test Kitchen, we talk about five main barriers that we typically face in conducting technology programming in our libraries: time, budget, skill, interest, and support. It’s our belief that most of these are not impossible barriers, but sometimes it’s hard to see how. Especially when things like your time and budget are already stretched paper thin.

On Tuesdays, we’re tackling the budget question with programs you can run at your library for under $10. We’re also addressing the interest and support questions by asking you to share your inexpensive STEM programs in the comments, and to let us know what kinds of feedback you’ve gotten when you’ve tried these or similar programs in your buildings! This week: Strawberry DNA Extraction

Cost: About $5 for strawberries and a bottle of rubbing alcohol; the other items are usually available around your home or workplace (and only needed in very small quantities)

Age Range: elementary-middle school

Difficulty: Easy to set up; explaining the procedure will take some staff preparation

Here’s what you’ll need:

 

1. The day before, put the bottle of rubbing alcohol in the freezer and keep it icy cold right up until you’re ready to use it.

2. Remove the stems from 2-3 strawberries, put them in a Ziploc bag and have the kids mash them up.

3. Create an “extraction buffer” with 1 cup water, 3/4 tsp. salt, and 3/4 tsp. dish soap or shampoo; add this solution to the mashed strawberry, and mash the bag well to mix it well.

4. Place the funnel over a glass, and a coffee filter into the funnel, and pour the mixture from the baggie into it; use a spoon to press as much through the filter as possible.

5. Carefully drop or pour the cold rubbing alcohol down the side of the glass. The mixture will separate into layers; the strawberry’s DNA is the white mucous-like substance on top. You can remove it with a craft stick or coffee stirrer to examine it more closely.

This activity works well in a program with a discussion about DNA in general, solubility of liquids, forensic investigations, or even gardening.

I learned about the procedure from Cool Forensic Tools by Esther Beck, 2009.