Array of micro-epidermal actuators for noninvasive pediatric flexible conductive hearing aids.

Corrective surgeries and implantable aids are highly invasive for pediatric patients with conductive hearing loss. Flexible hearing aids are a noninvasive solution to address pediatric hearing loss. These aids generate vibrations on epidermal layer of skin behind the ear using micro-epidermal actuators to bypass the auditory canal. However, the major challenge is to generate a strong level of vibrations that can reach cochlea. Here, we designed, fabricated, and characterized arrays of micro-epidermal actuators to increase the vibration level from the flexible aids, improve frequency response and control the directionality of vibrations. Our human subject study showed that the flexible hearing aid with an array of actuators improved the hearing threshold by an average of 13.8 dB at 500 Hz, compared to a device with a single actuator. Also, the flexible aid with two actuators enhanced the hearing threshold by 30.5 dB at 1 kHz and 20.5 dB across 0.25-8 kHz versus unaided hearing.