This experiment explores the possibilities of generating interactive and adaptive interior environments by combining the use of conductive paint as a decorative and electronic component with a simple mechanism.
You can control the curtains in your room through a conductive paint capacitive touch sensor that can also become a decorative element. When a person touches the sensor the mechanism is activated, it deactivates when the sensor is not being touched.
The project was developed as part of the TfCD course of the Integrated Product Design Master programme at TU Delft.
Step 1: Components
- Arduino Uno
- Black acrylic paint
- PVA glue
- 10 kΩ resistor - Bowl - Blender
- Servo Motor DF15RSMG
- Breadboard / printboard
- MDF 6mm 500x1200
- Paper clip
- 3D printed gears
- Timing belt
- Steel bar 4mm
- Super Glue
- Double sided tape - Screw
Step 2: Making Conductive Paint
You can choose from buying conductive paint or making your own. Make sure you have a strong blender available if you choose to make your own paint.
Follow the instructions from the link https://www.instructables.com/id/1-DIY-Conductive-Ink/ to elaborate the DIY conductive ink. Basically, you will have to burn the carbon, select the ones with a low resistance in order to be more conductive (<100 Ohms, use a multimeter). Blend it with water. Let the mix sit for 2 hours. Remove the excess of water from the top and finally add glue and acrylic paint.
As a final step to this part of the process, you will have to paint in a piece of paper, for this project we painted a rectangle but feel free to paint the form that you wish and best goes with your interior.
Step 3: Laser Cutting MDF Rail
Adapt the design and size of the rail in the .dxf file according to the length of your curtain. You can also design your own rail considering a “T” structure and simple tenons assembly. Draw the pieces on a 2D CAD software and proceed to laser cutting your pieces in the 6mm MDF plate.
Step 4: Gears
Consider buying 2 aluminum gears (40mm diam and 2mm step) or obtain them from any 3D model open source to 3D print them. These gears will be connecting the engine to the timing belt.
Assemble the two MDF pieces that were laser cut using super glue. Assemble the rest of the pieces to form the motor support, follow the images.
Step 6: Attach Motor
Assemble the Servo Motor to the side of MDF Structure with the screws. *Make sure to test the circuit before fixing the motor (See step 7)
Step 7: Assemble Mechanism
Connect the gears to the rail, one will be fixed (at the end of the mechanism) and the other one can be removed (moving part of the motor). The fixed gear is assembled to the rail with the solid steel 4mm bar.
Once you have the distance between the two gears, use it to measure how long the timing belt has to be. Before assembling the two ends of the timing belt, reduce the obtained distance by 3 mm to obtain more tension. The two ends of the timing belt can be sewed or connected with textile tape. Sew the piece that connects to the curtain to the timing band. This piece can be made with a piece of ribbon or textile, attached to an office clip on the other end.
Connect the timing belt to the fixed gear and pull it until it meets the motor gear on the other end of the rail.
Step 8: Programming Motor and Capacitive Sensor
Copy and paste the sketch into the Arduino IDE. Connect the servo motor and conductive paint sensor to the Arduino and Protoboard following the images above. *Make sure to test the circuit before fixing the motor.
The paint will work as a touch sensor that activates the servo motor when touched and deactivates the motor when not touched.
Step 9: Attach to Ceiling
With a double-sided tape, stick the main structure to the ceiling 3cm parallel to you curtain rail. Make sure your curtain doesn’t get stuck in the mechanism. Attach the timing band to the end of the curtain.
Step 10: Activate It!
Attach your painted paper to the wall.
You will only need to touch the paint when you want the mechanism to start! :)