The mounting demand for sustainable, self-powered biomedical devices, particularly those engineered for extreme environments, has established triboelectric nanogenerators (TENGs) as a prominent technology in energy harvesting research. This review examines state-of-the-art biomaterial synthesis strategies essential for developing high-performance bioelectronic TENGs that can operate reliably under harsh conditions, including elevated temperatures, extreme humidity, and mechanical strain. It begins with a comprehensive overview of the fundamental principles of triboelectricity and subsequently addresses the pivotal challenges associated with efficient charge generation and retention in such challenging settings. The content places particular emphasis on recent advancements in composite material engineering and structure design for high-efficiency mechanisms, with a particular focus on biocompatible and environmentally resilient materials. The integration of TENGs into wearable sensors, implantable devices, and self-powered monitoring systems is also investigated, demonstrating their transformative potential for bioelectronic applications. Our goal subsequently underscores persistent limitations to overcome, including those pertaining to fabrication scalability and long-term operational stability, while concurrently proposing prospective research directions. Consequently, this work underscores how innovative biomaterial synthesis and bioelectronic devices can enable the development of next-generation, high-performance, self-powered devices suited for extreme biomedical environments.
Piezoelectric generators use direct piezoelectric effects that convert mechanical energy into electrical energy. Many studies were attempted to fabricate piezoelectric generators using piezoelectrics such as ZnO, PZT, PVDF. However, these various inorganic/organic piezoelectric materials are not suitable for bio-implantable devices due to problems such as brittleness, toxicity, bio-incompatibility, bio-degradation. Thus, in this paper, piezoelectric generators were prepared using a silk fibroin film which is bio-compatible by dip-coating method. The silk fibroin films are a mixed state of silk I and silk II having stable β- sheet type structures and shows the d33 value of 8~10 pC/N. There was a difference in output voltages according to the thickness. The silk fibroin generators, coated 10 times and 20 times, revealed the power density of 16.07 μW/㎠ and 35.31 μW/㎠ using pushing tester, respectively. The silk fibroin generators are sensitive to various pressure levels, which may arise from body motions such as finger tapping, foot pressing, wrist shaking, etc. The silk fibroin piezoelectric generators with bio-compatibility shows the applicability as a low-power implantable piezoelectric generator, healthcare monitoring service, and biotherapy devices.