Biomolecular self-assembly presents a convenient and promising approach for fabricating functional nanomaterials. The inherent structural and functional diversity of biomolecules facilitates the creation of a wide spectrum of biological nanomaterials through this intricate process. These versatile materials have demonstrated extensive utility in multidisciplinary domains, encompassing materials science, biomedical engineering, tissue engineering, nanotechnology, and analytical science. This review focuses on self-assembled biomolecular materials for energy harvesting applications, organized into 4 main aspects. Firstly, we introduce the self-assembly methods and key factors involved in biomolecular self-assembly mechanism, including hydrogen bonding, covalent bonds, π–π interactions, electrostatic interactions, and hydrophobic/hydrophilic interactions. Secondly, we discussed the structural characteristics of different types of self-assembled biomolecular materials and introduced their mechanical, piezoelectric, ferroelectric, semiconductor, and biocompatibility properties. Next, the application of self-assembled biomolecular materials in energy harvesting was studied, mainly focusing on piezoelectric nanogenerators, triboelectric nanogenerators, water-enabled electricity generation, and other types of energy harvesting devices. Finally, we emphasized challenges in the area encompassing not only the design of the materials and assembly regulation but also probable efforts in improving performance and application fields. We believe that this review will elucidate diverse functions of self-assembled biomaterials, paving the way for the innovative design of biomaterials not only for energy harvesting systems but also for biomaterial-based microelectronic devices.
| 1. | Molecular design and assembly regulation: The limited knowledge of the self-assembly potential of different kinds of biomolecules and the lack of fundamental understanding of the self-assembly process markedly restricted the development of new biomaterials. Experimental and theoretical research efforts are needed to examine the self-assembly process of amino acids, peptides, protein, metabolites, and other biomolecules, establishing the foundation for the design and fabrication of functional self-assembled biomaterials. |
| 2. | Performance and long-term stability: In addition to further improving the mechanical, piezoelectric, and other physical properties, addressing the fundamental challenges of energy conversion efficiency, power output density, and long-term stability is paramount for translating biomolecular self-assemblies into practical devices. Self-assembled biomaterial-based devices exhibit significantly lower power densities than traditional technologies. To narrow this gap, synergistically modifying with piezoelectric/conductive fillers, optimizing device structures to improve interfacial charge transfer, and constructing piezoelectric–triboelectric hybrid systems to compensate for single-mechanism limitations are effective strategies [151–153]. While biomaterial-based devices lag behind synthetic inorganic materials in conversion efficiency, their core value lies in biocompatibility-dependent and context-appropriate energy output scenarios. An integrated approach combining performance enhancement, stability assurance, and lifecycle regulation will facilitate their transition from laboratory research to practical use. Additionally, their operational stability in complex humid environments remains a key bottleneck. To overcome this, material engineering strategies like chemical cross-linking and the development of robust composite materials are useful strategies [154,155]. Furthermore, biomaterials are prone to degradation under harsh conditions, leading to mechanical strength loss after wearable use and power drop after water immersion. To address this problem, physical surface coating or waterproof encapsulation layers can shield these delicate structures from degradation [156]. |
| 3. | Practical applications: Although many applications have been proposed and demonstrated for biomolecular selfassemblies, many challenges need to be overcame before they can be put into practical usage. The first challenge will be the massive production of high-quality materials. Most synthesis methods used in laboratory may not be adopted for industrial production. In addition, the impact of selfassembled micro- and nanostructures for the living system are largely unknown. To address this, researchers can explore low-cost biomass precursors and green solvents to reduce costs, and develop continuous-flow microfluidic self-assembly technologies [157,158] to precisely regulate intermolecular interactions for large-volume uniform production. Moving from laboratory synthesis to industrial production requires improving the controllability of self-assembly and batch-to-batch consistency. This can be achieved by optimizing reaction parameters through machine learning-driven design and implementing automated quality control to validate product uniformity [159,160]. Standardization of performance evaluation for bio-based energy harvesters is another key hurdle, as a lack of unified metrics hinders fair comparison and optimization.To address this issue, a consensus-based framework can be developed through interdisciplinary collaboration to define the core metrics for systematic evaluation. Furthermore, integration with existing microelectronic systems needs dedicated research for seamless functionality. Creating compatible interface architectures can bridge the material and functional gaps. Beyond manufacturing and standardization, biological implications require thorough investigation. The establishment of a multidimensional biocompatibility assessment platform allows for the characterization of immune responses and informs risk-mitigating structural modification. |
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |