Dispenser-printed sound-emitting fabrics for applications in the creative fashion and smart architecture industry

Abstract

This paper presents a printing technology for the design and manufacture of interactive planar speakers. With this technology, sound emission can be easily integrated into various textiles at the design stage with minimal assembly after printing. This paper reports direct write dispenser printed sound emitting smart fabrics, aimed at creative fashion and smart architecture applications opening up new opportunities in product design. Planar spiral speakers generate a membrane vibration and so emit sound when driven from an a.c. audio source if a magnet is in close proximity to the spiral. These speakers are simpler to manufacture than conventional electromagnetic speakers and can be integrated on fabrics to form the basis of clothing in fashion applications. The speaker designs were printed on woven polyester fabric and produced a measured peak sound output level of 85 dB referenced to a reference sound pressure in air of 2×10-5 Pa. The printed fabric speakers demonstrate a wide frequency response from 20 Hz to 20 kHz. This research demonstrates a straightforward fabrication method, based on dispenser printing, to achieve sound emission from a fabric. The fabrication process requires a processing temperature of 130 o C for 10 minutes which is compatible with the majority of fabrics which are used in the fashion and architecture industries. This fabrication method is a direct write technique offering no waste and achieves a conductor resistivity of 7.69×10-6 Ω•m. This paper reports on the theory and the manufacturing technology to achieve direct write dispenser printed planar spiral speakers on fabrics.

Towards The Internet of Smart Clothing: A Review on IoT Wearables and Garments for Creating Intelligent Connected E-Textiles

“…They show light and image information through Light-Emitting Diodes (LEDs), optical fiber or displays (e.g., Liquid-Crystal Displays (LCDs) or electronic-ink displays (e-ink displays)). • Sound [75]. They emit sound and voice through buzzers, loudspeakers, headphones, in-earphones or speech synthesizers.…”

E-Textiles for Healthy Ageing

“…Piezoelectric materials such as PVDF have also been used [108] to enhance the sound pressure. Current driven printed conductive spirals on textile have been combined with a permanent magnet to generate sound [109]. Research is required to increase the actuating force of the active materials whilst retaining compatibility with fabrics, improve coupling between the actuating materials and the textile and investigate the influence of garment design on speaker performance.…”

Enabling platform technology for smart fabric design and printing

“…Berkeley University have dispenser printed onto a flexible polyimide substrate creating a thermoelectric generator, 9 lithium-ion batteries and an electrochemical capacitor 10 and a zinc ink deposited on silicon provided the proof mass in an accelerometer. 11 Dispenser printed smart fabrics have also been demonstrated for the functions of sound emission, 12 electroluminescence, 13 colour change, 14,15 stretch sensing 16 and proximity sensing. 17 However, each of these demonstrators was printed as single devices with individually programmed printer paths for each layer – this is unsuitable for the targeted creative industry users because of the complexity involved and the specific printing knowledge required.…”

“…This demonstrator shows the proximity sensor and electroluminescent lamps, but the same process occurs for the printed speaker, 12 which uses the conductor and dielectric layers, and the printed thermochromic display, 15 which uses the conductor and thermochromic layers.…”