Creation of Nanometer-Sized Features in Polysilicon Using Fusing

2001 ◽  
Author(s):  
Jeremy A. Levitan ◽  
Dan Good ◽  
Michael J. Sinclair ◽  
Joseph M. Jacobson
Keyword(s):  
Structural Change ◽  
Small Perturbation ◽  
Biological Systems ◽  
Fabrication Process ◽  
Length Scales ◽  
Physical Methods ◽  
Necked Region ◽  
Single Electrons ◽  
Novel Processes

Abstract Current microfabrication systems can achieve resolutions of approximately 0.1μm. We present physical methods for creating structures with length scales and characteristic dimensions significantly below current fabrication resolutions. These structures, themselves fabricated in conventional, gross-resolution (greater than 2μm) semiconductor facilities, undergo structural change to create features below the lithography limits of the fabrication process. These devices — dog-boned microfabricated polysilicon fuses — are heated just below melting, and a small perturbation current heats a narrow, necked region of the beam, resulting in fusing. Infrastructure has already been constructed to create gross-resolution structures in microfabrication. Novel processes and mechanisms are needed to utilize these resolutions and create structures capable of addressing biological systems, functioning quantum mechanically, use single electrons, or require extreme speeds.

scholarly journals Synthesis and patterning of tunable multiscale materials with engineered cells

2014 ◽  
Author(s):  
Allen Y Chen ◽  
Urartu O.S. Seker ◽  
Michelle Y Lu ◽  
Robert J Citorik ◽  
Timothy Lu
Keyword(s):  
Composite Materials ◽  
Materials Science ◽  
Biological Systems ◽  
Inorganic Materials ◽  
Length Scales ◽  
Multiscale Materials ◽  
Self Assembling ◽  
Multiple Length Scales ◽  
Synthetic Cell ◽  
Environmentally Responsive

A major challenge in materials science is to create self-assembling, functional, and environmentally responsive materials which can be patterned across multiple length scales. Natural biological systems, such as biofilms, shells, and skeletal tissues, implement dynamic regulatory programs to assemble complex multiscale materials comprised of living and non-living components. Such systems can provide inspiration for the design of heterogeneous functional systems which integrate biotic and abiotic materials via hierarchical self-assembly. Here, we present a synthetic-biology platform for synthesizing and patterning self-assembled functional amyloid materials across multiple length scales with bacterial biofilms. We engineered Escherichia coli curli amyloid production under the tight control of synthetic regulatory circuits and interfaced amyloids with inorganic materials to create a biofilm-based electrical switch whose conductance can be selectively toggled by specific environmental signals. Furthermore, we externally tuned synthetic biofilms to build nanoscale amyloid biomaterials with different structure and composition through the controlled expression of their constituent subunits with artificial gene circuits. By using synthetic cell-cell communication, our engineered biofilms can also autonomously manufacture dynamic materials whose structure and composition change with time. In addition, we show that by combining subunit-level protein engineering, controlled genetic expression of self-assembling subunit proteins, and macroscale spatial gradients, synthetic biofilms can pattern protein biomaterials across multiple length scales. This work lays a foundation for synthesizing, patterning, and controlling composite materials with engineered biological systems. We envision that this approach can be expanded to other cellular and biomaterials contexts for the construction of self-organizing, environmentally responsive, and tunable multiscale composite materials with heterogeneous functionalities. Now published as: Nature Materials, doi:10.1038/nmat3912

scholarly journals Spatial heterogeneity of the cytosol revealed by machine learning-based 3D particle tracking

2020 ◽  
Vol 31 (14) ◽  
pp. 1498-1511 ◽  
Author(s):  
Grace A. McLaughlin ◽  
Erin M. Langdon ◽  
John M. Crutchley ◽  
Liam J. Holt ◽  
M. Gregory Forest ◽  
...  
Keyword(s):  
Machine Learning ◽  
Spatial Heterogeneity ◽  
Particle Tracking ◽  
Cell Biology ◽  
Physical State ◽  
Biological Systems ◽  
Physical Structure ◽  
Length Scales ◽  
3D Motion ◽  
In Cells

The structure of the cytosol across different length scales is a debated topic in cell biology. Here we present tools to measure the physical state of the cytosol by analyzing the 3D motion of nanoparticles expressed in cells. We find evidence that the physical structure of the cytosol is a fundamental source of variability in biological systems.

Fabrication of Nanomechanical Biosensors to Map 3D Surface Strain in Live Cells and Tissue

2020 ◽  
Author(s):  
Daniel J. Shiwarski ◽  
Joshua W. Tashman ◽  
Alkiviadis Tsamis ◽  
Jacqueline M. Bliley ◽  
Malachi A. Blundon ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Spatial Resolution ◽  
Microcontact Printing ◽  
Fluorescent Dye ◽  
Fabrication Process ◽  
Surface Strain ◽  
Live Cells ◽  
Pattern Design ◽  
Length Scales ◽  
Material Preparation

Abstract This protocol details the step-by-step fabrication process to create an extracellular matrix (ECM) protein-based nanomechanical biosensor (NMBS) via an adaptation of the surface-initiated assembly (SIA) procedure1. The NMBS is a fluorescently labeled, ultra-thin fibronectin lattice-mesh with spatial resolution tailored by adjusting the width and spacing of the lattice from 2-100 µm. By applying the NMBS to the surface of cells and tissues one can directly measure deformation from subcellular to tissue length-scales. The procedure outlined here covers all aspects of NMBS construction from pattern design, photolithography for mold creation, casting of polydimethylsiloxane (PDMS) silicone stamps, conjugation of fluorescent dye to fibronectin, microcontact printing of fibronectin, creation of gelatin carriers2, transfer of the NMBS to gelatin carriers, and the use of gelatin carriers for application of the NMBS onto cells and tissue. The protocol can be broken down into three phases: material preparation (2 days), NMBS patterning (4 hours), and transfer to cell or tissue (1 hour). Material preparation and NMBS patterning can be performed ahead of time and the patterned NMBS can be stored for up to 1 year prior to use.

The use of physical methods to locate metal ions in biological systems

1991 ◽  
Vol 43 (2-3) ◽  
pp. 384
Author(s):  
M. Thellier ◽  
C. Ripoll ◽  
F. Sommer ◽  
E. Wittendorp-Rechenman ◽  
R. Rechenmann
Keyword(s):  
Metal Ions ◽  
Biological Systems ◽  
Physical Methods

Neutron Scattering in Structural Biology and Biomolecular Materials

MRS Bulletin ◽  
1999 ◽  
Vol 24 (12) ◽  
pp. 40-47 ◽  
Author(s):  
J. Kent Blasie ◽  
Peter Timmins
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Biological Systems ◽  
Inelastic Neutron ◽  
Hydrogen Atoms ◽  
Length Scales ◽  
Elastic Neutron ◽  
Neutron Sources ◽  
Structure And Dynamics ◽  
Scattering Technique

The substantial power of both elastic and inelastic neutron-scattering techniques for the investigation of the structure and dynamics of biological systems and related biomolecular-based materials—as with soft matter in the previous article by Lindner and Wignall—arises primarily from the essentially isomorphous nature of the substitution of deuterium for selected hydrogen atoms in these systems, coupled with the exquisite sensitivity of neutron scattering to this isotopic substitution. Since these systems are comprised of large macromolecules and supramolecular assemblies thereof, their essential structures and dynamics extend from the atomic scale up to very large length scales of the Order of 101–104 Å. Hence neutron sources and neutron-scattering spectrometers optimized for longer wavelength (or “cold”) thermal neutrons are necessary in order to most effectively address the structure and dynamics at the longer length scales inherent to these Systems.The large majority of previous neutron-scattering experiments on biological systems have been performed with reactor neutron sources. Some of the more significant of these are briefly summarized in the following sections. They may be categorized in terms of the nature of the intermolecular order, both orientational and positional, within the System of interest and either the elastic neutron-scattering technique employed to investigate their time-averaged structures or the inelastic neutron-scattering technique employed to investigate their dynamics.

scholarly journals Physical methods for investigating structural colours in biological systems

2009 ◽  
Vol 6 (suppl_2) ◽  
Author(s):  
P Vukusic ◽  
D.G Stavenga
Keyword(s):  
Biological Systems ◽  
Research Field ◽  
Structural Coloration ◽  
Physical Methods ◽  
Theoretical Approaches ◽  
Recent Developments ◽  
Photodiode Array ◽  
Engineered Systems ◽  
Behavioural Biology

Many biological systems are known to use structural colour effects to generate aspects of their appearance and visibility. The study of these phenomena has informed an eclectic group of fields ranging, for example, from evolutionary processes in behavioural biology to micro-optical devices in technologically engineered systems. However, biological photonic systems are invariably structurally and often compositionally more elaborate than most synthetically fabricated photonic systems. For this reason, an appropriate gamut of physical methods and investigative techniques must be applied correctly so that the systems' photonic behaviour may be appropriately understood. Here, we survey a broad range of the most commonly implemented, successfully used and recently innovated physical methods. We discuss the costs and benefits of various spectrometric methods and instruments, namely scatterometers, microspectrophotometers, fibre-optic-connected photodiode array spectrometers and integrating spheres. We then discuss the role of the materials' refractive index and several of the more commonly used theoretical approaches. Finally, we describe the recent developments in the research field of photonic crystals and the implications for the further study of structural coloration in animals.

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