Enosh Lim, along with Dr. Miriam Redleaf and Dr. Mohammad J. Moghimi, wrote in the 2025 publication “Array of micro-epidermal actuators for non-invasive paediatric flexible conductive hearing aids” in Communications Engineering (Nature Portfolio) that this is an important turning point where biomedical engineering crosses paths with otolaryngology in children. The innovative research presents an alternative to traditional invasive procedures for treating child conductive hearing loss (CHL) in the shape of flexible devices with integrated micro-epidermal actuators (MEAs).

The Innovation: From Concept to Human Testing
Children with congenitally or chronically acquired CHL are frequently confronted with the limitations of these traditional interventions—corrective operations or auditory osseointegrated implantation—which are invasive, costly, and poorly suited for early developmental periods. Even such extrinsic devices as bone-anchored hearing aids, in the opinion of the authors, are typically bulky, uncomfortable, and socially stigmatizing, especially in young children.

Lim, Redleaf, and Moghimi’s innovation is in creating thin, skin-compatible hearing aids with piezoelectric micro-actuators to directly send sound vibrations to the cochlea by bone conduction. The actuators are created with lead zirconium titanate (PZT-5H) due to its high piezoelectric coefficient, in a soft, skin-compliant PDMS (polydimethylsiloxane) substrate. The MEAs circumvent the outer and middle ear, offering a lifeline to children with atresia, canal stenosis, or chronic otitis media.

Technological Characterization: Finite Element Analysis and Experimental Validation
The authors provided an impressive synergy of theory and practice, initially simulating vibration propagation by finite element analysis (FEA) before being verified by actual experiments conducted in geometric shells and human skull models. Stacked and horizontal MEA array vibrations produced much stronger, spatially distributed patterns in comparison to individual transducer setups.

Most notable was phase-controlled construction and destructive interference engineering. By adjusting relative phase difference among actuators, the research team had the ability to direct vibrational energy in a specific direction, increasing sound perception in specific cochlear zones. The stacked array setup—in which two actuators are stacked in vertical orientation—was particularly resilient to phase fluctuation and soft tissue damping, yielding high-energy, reliable performance.

Clinical Translation: Human Subject Testing with Simulated Congenital Hearing Loss

Ten adult subjects with simulated CHL took part in the team’s controlled experiment with earplugs in addition to earmuffs. The results were impressive: stacked MEA array increased hearing thresholds by as much as 13.8 dB at 500 Hz, with comparable gains throughout the range of 0.25–8 kHz. The voltage needed to elicit auditory perception was also reduced by 71%, which highlights energy efficiency and sensitivity gains through the use of the actuator array.

Most notably, phase modulation was associated with changes in directional perception in some participants, who heard sound from either the opposite ear or from the occipital area. This opens interesting prospects for bilateral stimulation or transcranial signal routing, particularly in unilateral CHL in children.

A Testimony to Interdisciplinary Cooperation
This work is also a testament to the strength of collaboration across disciplines. Wake Forest University Department of Biomedical Engineering and Center for Artificial Intelligence Research’s Dr. Moghimi contributed expertise in system integration and computational modeling. Clinical insight from senior otolaryngologist, Dr. Miriam Redleaf, ensured that whatever solution is developed is suitable for actual needs in children. The team’s use of MEMS microphones, flexible polyimide-based circuits, and biomedical material engineering combine to put this in the category of actual realized medical device prototype rather than theory.

Support from various organizations—including Rowan University, the Wake Forest School of Medicine, and the National Institute on Deafness and Other Communication Disorders (NIDCD)—further highlights how important this work is in academic as well as in clinical circles.

Social & Clinical Impact
The consequences of this development are far-reaching:

  • Non-invasiveness: Paediatric patients will not have to undergo surgery, hospitalization, or
  • Affordability and Accessibility: The use of low-cost PDMS and scalable manufacturing methods makes the device suitable for mass deployment, especially in low-resource settings.
  • Child Acceptance: Discreet in design, similar to a Band-Aid®, acceptance reduces stigma to enhance adoption and use among children.
  • Clinical Versatility: The frequency responses and customizable configurations of actuator arrays allow them to be adapted to specific anatomical and audiological profiles.

Future Perspectives and Ethical Considerations
The authors suggest eventual updates such as frequency equalizers, gain controls with adjustable settings by customers, and more power optimization to maximize battery longevity. Such improvements will be important for eventual deployment in everyday applications in children. The ethical strength of this work is also to be lauded. It adhered to IRB guidelines, placed emphasis upon informed consent, and openly revealed competing interests. The patent filing by Dr. Moghimi and his proposals for multi-center trials have an obvious path to regulatory approval and subsequent commercialization.

Summary

This is a shift in paradigms in hearing care for children, not just an engineering breakthrough but also as a socially responsible innovation. Through their placement of high-performance piezoelectric arrays in bendable, skin-compliant substrates, the authors present an elegant, efficient, and cost-effective hearing solution for millions of children globally. It is work to be highly valued—not just for the genius engineering involved but for its capacity to change lives in children.

Dr. Prahlada N.B
MBBS (JJMMC), MS (PGIMER, Chandigarh). 
MBA in Healthcare & Hospital Management (BITS, Pilani), 
Postgraduate Certificate in Technology Leadership and Innovation (MIT, USA)
Executive Programme in Strategic Management (IIM, Lucknow)
Senior Management Programme in Healthcare Management (IIM, Kozhikode)
Advanced Certificate in AI for Digital Health and Imaging Program (IISc, Bengaluru). 

Senior Professor and former Head, 
Department of ENT-Head & Neck Surgery, Skull Base Surgery, Cochlear Implant Surgery. 
Basaveshwara Medical College & Hospital, Chitradurga, Karnataka, India. 

My Vision: I don’t want to be a genius.  I want to be a person with a bundle of experience. 

My Mission: Help others achieve their life’s objectives in my presence or absence!

My Values:  Creating value for others. 

Reference:

Lim E, Redleaf M, Moghimi MJ. Array of micro-epidermal actuators for noninvasive pediatric flexible conductive hearing aids. Communications Engineering. 2025;4:28. https://doi.org/10.1038/s44172-025-00369-7

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