Development of Flexible and Functional Sequins Using Subtractive Technology and 3D Printing for Embroidered Wearable Textile Applications

Abstract

Embroidery is often the preferred technology when rigid circuit boards need to be connected to sensors and electrodes by data transmission lines and integrated into textiles. Moreover, conventional circuit boards, like Lilypad Arduino, commonly lack softness and flexibility. One approach to overcome this drawback can be flexible sequins as a substrate carrier for circuit boards. In this paper, such an approach of the development of flexible and functional sequins and circuit boards for wearable textile applications using subtractive and additive technology is demonstrated. Applying these techniques, one-sided sequins and circuit boards are produced using wax printing and etching copper-clad foils, as well as using dual 3D printing of conventional isolating and electrically conductive materials. The resulting flexible and functional sequins are equipped with surface mounted devices, applied to textiles by an automated embroidery process and contacted with a conductive embroidery thread.

Keywords: 3D printing; additive manufacturing; circuit boards; functional sequins; subtractive technology; wearable electronics.

Figure 1

(a) Embroidered light for acoustic ceilings [6] (b) Smart glove [8] (c) Jacquard Trucker Jacket Levi’s^® [4] (d) EKG shirt with embroidered electrical interconnections [7] (e) Embroidered heating jacket [11].

Figure 2

Subtractive technology (a) masking of the positive circuit pattern (b) etching of the non-masked surface (c) removing masking.

Figure 3

Additive technology (a) masking of the negative circuit pattern (b) copper deposition (c) removing masking.

Figure 4

(a) Printed flexible circuit board [22] (b) Printed temperature sensor using inkjet printer [21] (c) Subtractive printing [23] (d) Intelligent contact lens using inkjet printing [25].

Figure 5

(a) Dual 3D printed circuit board (A) Inserting a LED component (B) Printing conductive traces (C) Embedded LED (D) Attached battery [30] (b) Dual 3D printing on textile fabric [29].

Figure 6

(a) Filling the wax and preparing the print of conductor pattern (b) Wax printing process (c) Etching process.

Figure 7

(a) Single-layer two-pole LED sequin tape designs and (b) multi-pole RGB sequin tape designs.

Figure 8

Printed single-layer LED and RGB sequin tapes on PET film with copper adhesive tape.

Figure 9

Printed single-layer LED and RGB sequin tapes on copper-clad film.

Figure 10

Printed sequin tapes: (a) LED sequin tapes and (b) RGB sequin tapes.

Figure 11

Single-layer sequin designs for (a) LED sequins designs and (b) RGB sequins.

Figure 12

3D printed sequins with conductive copper foil structures: (a) PLA LED sequins and (b) PLA RGB sequin.

Figure 13

Microscopic images of the deposited gold layers. (a) PVA reservation without deposited gold layer at the top and the sequin ribbon with three coated gold layers at the bottom (b) three gold layers at the top and four gold layers at the bottom (c) four layers of gold particles on the top and five gold layers on the bottom.

Figure 14

3D sequin designs for (a) LEDs and (b) RGBs.

Figure 15

3D printed single-layer LED sequins and sequin tapes with different print cores and various 3D printing materials.

Figure 16

3D printed single-layer RGB sequins with different print cores and various 3D printing materials.

Figure 17

3D printed LED and RGB sequins at 95% material flow with the conductive filament Electrifi from Multi3D (a) print head AA 0.4 (b) print head BB 0.4.

Figure 18

3D printed PLA LED sequins with conductive filament Electrifi from Multi3D and equipped with LEDs.

Figure 19

Embroidered circuit layouts: (a) Circuits for LED and RGB sequins without power source (b) overview of all Sequins with power source (c) LED sequins according to the subtractive technique (d) 3D printed LED sequins (e) RGB sequins by subtractive and additive technique.