Merging Biological Self‐Assembly with Synthetic Chemical Tailoring: The Potential for 3‐D Genetically Engineered Micro/Nano‐Devices (3‐D GEMS)

Abstract

Appreciable global efforts are underway to develop processes for fabricating three‐dimensional (3‐D) nanostructured assemblies for advanced devices. Widespread commercialization of such devices will require: (i) precise 3‐D fabrication of chemically tailored structures on a fine scale and (ii) mass production of such structures on a large scale. These often‐conflicting demands can be addressed with a revolutionary new paradigm that couples biological self‐assembly with synthetic chemistry: Bioclastic and Shape‐preserving Inorganic Conversion (BaSIC). Nature provides numerous examples of microorganisms that assemble biominerals into intricate 3‐D structures. Among the most spectacular of these microorganisms are diatoms (unicellular algae). Each of the tens of thousands of diatom species assembles silica nanoparticles into a microshell with a distinct 3‐D shape and pattern of fine (nanoscale) features. The repeated doubling associated with biological reproduction enables enormous numbers of such 3‐D microshells to be generated (e.g., only 40 reproduction cycles can yield >1 trillion 3‐D replicas!). Such genetic precision and massive parallelism are highly attractive for device manufacturing. However, the natural chemistries assembled by diatoms (and other microorganisms) are rather limited. With BaSIC processes, biogenic assemblies can be converted into a wide variety of new functional chemistries, while preserving the 3‐D morphologies. Ongoing advances in genetic engineering promise to yield microorganisms tailored to assemble nanoparticle structures with device‐specific shapes. Large‐scale culturing of such genetically tailored microorganisms, coupled with shape‐preserving chemical conversion (via BaSIC processes), would then provide low‐cost 3‐D Genetically Engineered Micro/nano‐devices (3‐D GEMs).

Biotemplated Materials for Sustainable Energy and Environment: Current Status and Challenges

“…For example, metal oxides were produced through methods involving gas/solid displacement reactions, [145,146,275] wet chemical processes, [279,147] or ALD. [143] Sandhage et al developed shape-preserving, gas/silica displacement reactions to convert diatom frustules into various metal oxides.…”

“…By using diatoms as templates, a number of materials with a potential for gas sensing application, particularly metal oxides and metals with hierarchical porous structures, have been obtained. For example, metal oxides were produced through methods involving gas/solid displacement reactions, [145,146,275] wet chemical processes, [279,147] or ALD. [143] Sandhage et al developed shape-preserving, gas/silica displacement reactions to convert diatom frustules into various metal oxides.…”

The place of diatoms in the biofuels industry

“…Diatoms make nanostructured silica in a variety of shapes that cannot be achieved by current synthetic materials approaches. Silica has limited properties as a material but several approaches have been developed by which diatom silica can either be directly converted or used as a template to generate a completely different chemistry while maintaining the nanoscale structure [174].…”

Calcined and natural frustules filled epoxy matrices: The effect of volume fraction on the tensile and compression behavior

“…Diatomaceous earth is an abundant, inexpensive material and extensively used in sound and heat insulation, abrasives, filters, absorbents and explosives [8]. One potential engineering application is the templates or scaffolds for the processing of three-dimensional complex micro-scale polymeric, metallic and ceramic structures [7,[9][10][11]. The other potential applications include gas-selective metal film membranes, pin-point drug delivery (magnetized frustules) and processing nano-powder silica (high-energy ball milling, ultrasonic waves and electrical and thermal shock) [12].…”