Tube-Balloon Logic for the Exploration of Fluidic Control Elements

Overview:

The Tube-balloon logic (TBL) device is a low cost technology which is intended to use as a logic gate for control of pneumatically driven systems. The TBL device is made from straws, tubing, and balloons, takes a novice five minutes to fabricate, and costs $0.45. It can be configured as NOT-, NAND-, and NOR-gates and assembled into a three-ring oscillator. It can also operate at pressures of up to 200 kPa and oscillate at frequencies of up to 15 Hz. We demonstrate its usage for a vibrating sieve that separates sugar from rice along with the the fabrication process in the video.

Tube Balloon Logic device

Video

Video_Tube.balloon.logic_Demo.and.fabrication.mp4

INSTRUCTION MANUAL

Overview of Materials:

• Flexible PVC tubing (Model Name: PVC tubing (inner diameter 1 mm), Supplier: mcmaster.com, Unit cost: $0.29 / 30cm)
• Balloon (Model Name: Koogel 260Q (Twisting balloon), Supplier: Amazon.com, Unit cost: $0.05)
• Straws (Model Name: ALINK 100 1/2" (Boba Straw), Supplier: Amazon.com, Unit cost: $0.08)
• Parafilm tape (Model Name: Parafilm M , Supplier: Amazon.com, Unit cost: $0.03 / 6 cm2)
• Scissor
• Hole puncher
• Scale
• Marker

Fabrication of Tube Balloon Logic (TBL) device:

1. Mark the straws (diameter of 12.7 mm) at 40 mm pieces and cut it into two pieces
2. Fold one piece of the straw in the middle to create a bendable layer (with a heart-like shape)
3. Insert the bendable layer into the outer straw
4. Punch holes into both straws as an inlet for the PVC tubing using a hole puncher
5. Cut the flexible PVC tubing (inner diameter of 1 mm) into two pieces of ~7.5 cm in length
6. Feed a one piece of PVC tubing through both straws (bendable layer and outer straw)
7. Cut the balloon to 20 cm length, pushed it over the other piece of tubing with an overlap of 1 cm
8. Use Parafilm to seal the balloon to the tubing.
9. Insert the balloon inside the outer straw such that it lays in between the outer straw and the bendable straw layer
10. Use Parafilm to fix the tubing to the straw.
11. Seal another end of the staws to ensure balloon cannot overinflate
12. Congradulations, you have successfully fabricated TBL device
13. Now your device is ready for testing!

Testing:

1. Use any air pump as a pressure source device which delivers pressure upto 200 kPa
2. Connect air supply to inflate balloon and to the PVC tubing as an inlet
3. When the balloon inflates, it kinks the tubing, and blocks pressure supply
4. When the balloon deflates, tubing gets unkinked, unblocking pressure supply
5. The maximum working pressure of TBL device will differ with the size and materials used for fabrication

Prerequisites:

1. User should be of min. 10 years age
2. A basic understanding of pneumatics is also recommended.

Tips:

• User may use different dimentions of the straws, tubing, and balloon, it will still work depending on the fabrication
• Make sure you wear ear buds to prevent hearing problems if balloon bursts.