Bio-manufacturing technology based on diatom micro- and nanostructure

Abstract

Diatom frustules, considered as novel bio-functional materials, display a diversity of patterns and unique micro-and nanostructures which may be useful in many areas of application. Existing devices directly use the original structure of the biosilica frustules, limiting their function and structural scale. Current research into the shapes, materials and structural properties of frustules are considered; a series of frustule processing methods including structure processing, material modification, bonding and assembly techniques are reviewed and discussed. The aim is to improve the function of diatom frustules allowing them to meet the design requirements of different types of micro devices. In addition, the importance of the comprehensive use of diatom processing methods in device research is discussed using biosensors and solar cells as examples, and the potential of bio-manufacturing technology based on diatom frustules is examined. Nature presents a wide range of functional structures. Particularly at the micro-and nanoscale, the complexity and functionality of biological structures are far greater than those of equivalent artificial devices, making these biological structures an appropriate subject for biotechnology and bio-manufacturing [1,2]. In our previous studies, we have reported bio-limited forming [3] and bio-replication forming [4,5] methods for manufacturing functional particles or surface morphology from biological structures. Micro devices with highly desirable structure and characteristics could be produced from biological micro-or nanostructures. Single-celled diatoms are widely distributed in rivers, lakes and other water bodies, and have a fast (exponential) reproductive rate. The cell wall of a diatom known as the frustule, has a transparent structure composed of amorphous silica [6]. The frustule has good mechanical strength [7,8], a variety of three-dimensional (3D) shapes [9,10], multi-level nanopores and microstructures [11,12], large surface area and unique optical properties [13][14][15], making it a potential novel functional material for bio-manufacturing. Studies on theoretical understanding, manufacturing methods and functionalization of diatom frustules are ongoing. In the last two centuries, the importance of diatom frustules in the field of micro-and nanotechnology has become increasingly evident. The potential of frustules has been extensively explored by academics and for commercial application. The resulting new theories and techniques have found wide application, leading to the formation of a new interdisciplinary area of research called diatom-based bio-nanotechnology (or diatom nanotechnology) [16][17][18][19][20][21]. The potential for diatoms in device applications, such as high-sensitivity gas sensors [22], drug delivery devices [23], biocarriers for biosensors [24][25][26][27], micro-filters [12,28], solar cells, battery electrodes and electroluminescent display devices [19] has been examined. However, the direct

Progress and Opportunities in Soft Photonics and Biologically Inspired Optics

“…Recent work aimed at elucidating photonic structure formation in butterflies in situ shows great promise for revealing the processes underlying formation of functional biological micro‐ and nanoarchitectures . Research aimed at modifying diatom growth and exploring diatoms' versatility in optical applications also is expected to provide significant insights and benefits for the development of optical technologies . While learning about the processes governing biological material formation, we also can hope to glean useful insight into strategies for advancing synthetic manufacture of photonic materials.…”

Investigation of Tribological Performances for Porous Structure of Diatom Frustule with FSI Method

“…Figure 7(a) exhibits the velocity gradient for the nonporous structure, while it fluctuates significantly near the pores for the Coscinodiscus sp. frustule (e.g., marked off with 10 Advances in Condensed Matter Physics In this case, the frictional force for the porous frustule decreases according to (6) and further its friction coefficient decreases because of its enhanced load-carrying capacity, which can be observed from (7).…”

“…The most striking feature of the diatom is its elaborate frustule made up of grotesque amorphous silicon. Considerable researches available show that the main cause that the diatom has not been eliminated in the past tens of millions of years [2][3][4][5][6] is due to superior mechanical properties of its frustule, which is attracting the intense attention of researchers. Kröger [7] observed through SEM that the different diatom frustules exhibit diversity in their shapes and sizes.…”

Complex‐shaped microbial biominerals for nanotechnology

“…To date, investigations on the application of microbes for nanotechnology have mainly focused on diatoms and magnetotactic bacteria. Several aspects covered in this review have previously been addressed in overview articles on diatom‐based nanotechnology, and therefore we will here mainly focus on more recent developments. We will summarize only the studies on diatoms because the magnetite (Fe 3 O 4 ) and greigite (Fe 3 S 4 ) nanocrystals biosynthesized by magnetotatic bacteria exhibit non‐complex shapes.…”