In the context of our TextileUX research project, we developed Sonoflex, an embroidered dynamic speaker not requiring a permanent magnet or high voltages. Our speaker is thin, lightweight, flexible, and to some degree stretchable.
Sonoflex is made of 100% textiles and is fabricated by embroidering two flat spiral coils of technical yarn (enameled copper wire) onto a customary textile base using an off-the-shelf embroidery machine. Similar to conventional speakers, the coils are powered with an amplified audio signal to generate varying magnetic fields. The consequently attracting/repulsing substrate textiles, acting as membranes, generate audible acoustic waves. While Sonoflex is not meant to compete with professional speakers, it is valuable for applications such as notification, playback of lo-fi music, or ultrasonic communication, transforming wearable textiles to output devices.
In our research paper, we demonstrate our design and fabrication method. We evaluate the speaker’s acoustic properties with respect to several manufacturing parameters, such as diameter, spiral turn count and spacing, and investigate different substrate materials. We show that our speaker has a wide frequency range in the audible spectrum, while also demonstrating its use as an ultrasonic transducer. Conclusively we demonstrate several applications, such as audible notifications and data transfer via ultrasonic device communication.