工学的な人間の鼓膜：力学、モデリング、および材料からの教訓

The tympanic membrane (TM) plays a pivotal role in auditory transduction by converting acoustic signals into mechanical energy. Damage to the TM, whether from chronic perforations, infections, trauma, or pathological changes such as tympanosclerosis, can significantly impair its biomechanical function and lead to conductive hearing loss. Tympanoplasty remains the standard intervention, traditionally utilising autologous grafts such as temporalis fascia or cartilage. However, these biological materials present limitations, including donor site morbidity, variable mechanical properties, and potential for long-term resorption. To overcome these challenges, synthetic scaffolds engineered from polymers such as polylactic acid (PLA), polycaprolactone (PCL), and silk fibroin have emerged as promising alternatives. This review provides a comprehensive examination of the mechanical characteristics of both healthy and diseased tympanic membranes, offering insights into their structural integrity and mechanical performance. Emphasis is placed on key parameters such as thickness, Young's modulus, tensile strength, strain tolerance, and viscoelastic behaviour, drawing from ex vivo and in vivo studies. The discussion extends to computational strategies, particularly finite element modelling (FEM) and inverse FEM, which enable accurate simulation of TM responses under physiological and pathological conditions. By linking empirical mechanical data with computational analyses, this review supports the rational design of synthetic grafts that closely mimic native tissue properties. Additionally, emerging trends in TM tissue engineering, including 3D printing and biomimetic scaffolds, are also highlighted for their potential to improve surgical outcomes in tympanoplasty.