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ME 514

Final Update: Electronic Component Embedding in a FFF Printed Part

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Printing Update

The team focused on finalizing the design for embedding electronic components in the weeks after our last update. Design 3 was finalized for the finger mount ring type flash light. The design was printed at MakerSpace using TPU.

Figure1: Design 3 printed with TPU

 

The flashlight was designed to be small in size as well as light enough to fit on the user’s fingers. The dimensions for different features within the Design 3 were optimized to create enough space for embedding different components of a flashlight.

A set of flashlights was bought from Amazon to get all the necessary components for our final part. After the flashlight was broken into individual components, minor modifications on the features were needed in our design to fit all the necessary components. Design 4 was created to adjust to the updated requirements as well as to cut some materials on the part.

Figure 2: Design 4, CAD Models (top), FFF Printed Parts (bottom)

 

After confirming the suitability of Design 4 for electronic embedding, we put together different components. Figure 3 shows different components we planned to embed in the flash light Design 4.

Figure 3: Components to Embed in the flashlight

 

The details of the components are

  1. 20mm x 25mm x 0.5mm metal sheets – 2 pieces
  2. Thin metal wires 5 cm long – 1 piece
  3. LED Bulb – 1 piece
  4. 3V Coin type Lithium Ion batteries – 2 sets

The cutouts for the wires and metal sheets are shown in figure 4.

Figure4: Slots and cutouts for Wire and Metal Sheets in the design

The path for laying wires in the part can be seen in the figure 5.

Figure 5: Path for Wire Embedding

The printing process was paused and then the electronic components were put in the slots at the right layer height. Figure 6 shows the embedded components on our printed part.

Figure 6: Electronic embedded during the printing process

 

After embedding the components into the part, we were  able to complete the print to fully enclose all the components. The final print can be seen in figure 7.

Figure 7: Final printed part with components embedded in it.

 

Of course, we wanted to test the working of our electronic components embedded in the printed part. We put 2 batteries in the bottom slot with the metal sheets on both sides. This completed the circuit and turned the light on. Different views of the successful test of the flashlight are shown in figure 8.

Figure 8: Slots for battery and metal sheets (left), FFF printed flashlight with components embedded in it (right).

 

With the successful test of the part, we validate the feasibility of our idea of Electronic Component Embedding in a FFF printed part. The ‘print-pause-print’ strategy works just fine. Also, the design was printed without any support material.

Notes

Few points to consider for a successful design and print are

  1. The sizes of slots and cutouts have to be properly planned, including the resolution of print.
  2. Design should incorporate proper build orientation, overhang angles and bridge distances so as to create a successful print.
  3. The infill pattern and infill density should also be taken into consideration while printing the part with very small feature sizes (eg. slot widths).
  4. The printing process shouldn’t be paused for long. As the time for embedding increases, the printed layer starts to cool causing a poor binding between successive layers. Also, each time the extruder starts printing after a pause, little leftover material is deposited on the new layer causing a rough surface.
  5. Though TPU is a flexible material, it is very difficult to work with. The print failed couple of times because of the material itself. The surface finish of part printed with PLA is far better than the one printed with TPU.

 

Conclusion

A flashlight was designed, printed and tested to validate the idea of electronic component embedding in a FFF printed part. This opens up a new area of application for Additive manufacturing technology with potential markets in digital manufacturing of different components. The initial proposal mentions the possibility of printing Bio-Medical devices such as wearable temperature sensors, heart rate monitoring devices.With minor modifications in designs based on user requirements, multiple designs could be printed without any significant manual intervention.  If we could program the printers to ‘print-pause-print’ and then have robotic arms to embed components during the paused period, this could revolutionize the manufacturing industry.