Stochastic Computing via In Operando Modulation of Rectification in Molecular Tunneling Junctions

2020 ◽  
Author(s):  
Xinkai Qiu ◽  
Sylvia Rousseva ◽  
Gang Ye ◽  
Jan C. Hummelen ◽  
Ryan Chiechi
Keyword(s):  
Self Assembly ◽  
Variable Temperature ◽  
Self Assembled Monolayers ◽  
Microfluidic Channels ◽  
Proof Of Concept ◽  
Glycol Ethers ◽  
Stochastic Computing ◽  
Assembled Monolayers ◽  
In Operando ◽  
Tunneling Junctions

This paper describes the reconfiguration of molecular tunneling junctions during operation via the self-assembly of bilayers of glycol ethers. We use well-established functional groups to modulate the magnitude and direction of rectification in assembled tunneling junctions by exposing them to solutions containing different glycol ethers. Variable-temperature measurements establish that rectification occurs by a bias-dependent tunneling-hopping mechanism and that glycol ethers, beside being an unusually efficient tunneling medium, behave identically to alkanes. We fabricated memory bits from crossbar junctions prepared by injecting eutectic Ga-In into microfluidic channels. Two 8-bit registers were able to perform logical AND operations on bit strings encoded into chemical packets as microfluidic droplets that alter the composition of the crossbar junctions through self-assembly to effect memristor-like properties. This proof of concept work demonstrates the potential for fieldable molecular-electronic devices based on tunneling junctions of self-assembled monolayers and bilayers.

Stochastic Computing via In Operando Modulation of Rectification in Molecular Tunneling Junctions

2020 ◽  
Author(s):  
Xinkai Qiu ◽  
Sylvia Rousseva ◽  
Gang Ye ◽  
Jan C. Hummelen ◽  
Ryan Chiechi
Keyword(s):  
Self Assembly ◽  
Variable Temperature ◽  
Self Assembled Monolayers ◽  
Microfluidic Channels ◽  
Proof Of Concept ◽  
Glycol Ethers ◽  
Stochastic Computing ◽  
Assembled Monolayers ◽  
In Operando ◽  
Tunneling Junctions

This paper describes the reconfiguration of molecular tunneling junctions during operation via the self-assembly of bilayers of glycol ethers. We use well-established functional groups to modulate the magnitude and direction of rectification in assembled tunneling junctions by exposing them to solutions containing different glycol ethers. Variable-temperature measurements establish that rectification occurs by a bias-dependent tunneling-hopping mechanism and that glycol ethers, beside being an unusually efficient tunneling medium, behave identically to alkanes. We fabricated memory bits from crossbar junctions prepared by injecting eutectic Ga-In into microfluidic channels. Two 8-bit registers were able to perform logical AND operations on bit strings encoded into chemical packets as microfluidic droplets that alter the composition of the crossbar junctions through self-assembly to effect memristor-like properties. This proof of concept work demonstrates the potential for fieldable molecular-electronic devices based on tunneling junctions of self-assembled monolayers and bilayers.

Self-assembly of biomolecules at surfaces characterized by NEXAFS

2007 ◽  
Vol 85 (10) ◽  
pp. 793-800 ◽  
Author(s):  
Xiaosong Liu ◽  
Fan Zheng ◽  
A Jürgensen ◽  
V Perez-Dieste ◽  
D Y Petrovykh ◽  
...  
Keyword(s):  
Surface Science ◽  
Self Assembly ◽  
Ribonuclease A ◽  
Polarization Dependence ◽  
Biological Molecules ◽  
Self Assembled Monolayers ◽  
Peptide Bonds ◽  
Molecular Adsorbates ◽  
Dna Oligonucleotides ◽  
Assembled Monolayers

Surface science has made great strides towards tailoring surface properties via self-assembly of nanoscale molecular adsorbates. It is now possible to functionalize surfaces with complex biomolecules such as DNA and proteins. This brief overview shows how NEXAFS (near edge X-ray absorption fine structure spectroscopy) can be used to characterize the assembly of biological molecules at surfaces in atom- and orbital-specific fashion. To illustrate the range of applications, we begin with simple self-assembled monolayers (SAMs), proceed to SAMs with customized terminal groups, and finish with DNA oligonucleotides and Ribonuclease A, a small protein containing 124 amino acids. The N 1s absorption edge is particularly useful for characterizing DNA and proteins because it selectively interrogates the π* orbitals in nucleobases and the peptide bonds in proteins. Information about the orientation of molecular orbitals is obtained from the polarization dependence. Quantitative NEXAFS models explain the polarization dependence in terms of molecular orientation and structure.Key words: NEXAFS, bio-interfaces, ribonuclease A, immobilization, orientation.

Synthesis of Calixarene Derivatives in One Reaction System

2014 ◽  
Vol 1015 ◽  
pp. 594-597
Author(s):  
Bing Qing Cao ◽  
Qi Bin Huang ◽  
Yong Pan ◽  
Mo Lin Qin
Keyword(s):  
Self Assembly ◽  
Delay Line ◽  
Organophosphorus Compounds ◽  
Reaction System ◽  
Reference Value ◽  
Self Assembled Monolayers ◽  
Sensitive Film ◽  
Assembled Monolayers ◽  
Ft Ir ◽  
Substitute Reaction

This paper presents a effective approach for one new supermolecule function materia preparation, 25-(thioalkyl-alkoxy)-p-tertbutylcalix [4] arene with self-assembled monolayers character was synthesized by two-step nucleophilic substitute reaction in NaH-THF phase with p-tertbutylcalix [4] arene and dibromodecne . The structure of product was characterized by FT-IR, 1H NMR, 13C NMR and MALDI-TOF-MS. The self-assembly molecular imprinted film as the sensitive film was coated on the gold delay line of SAW sensors to detect for detecting organophosphorus compounds such as sarin, had important reference value in counter-terrorism.

scholarly journals Surface assembly and nanofabrication of 1,1,1-tris(mercaptomethyl)heptadecane on Au(111) studied with time-lapse atomic force microscopy

2014 ◽  
Vol 5 ◽  
pp. 26-35 ◽  
Author(s):  
Tian Tian ◽  
Burapol Singhana ◽  
Lauren E Englade-Franklin ◽  
Xianglin Zhai ◽  
T Randall Lee ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Time Lapse ◽  
Scanning Probe ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Assembly ◽  
Assembled Monolayers ◽  
Liquid Cell

The solution self-assembly of multidentate organothiols onto Au(111) was studied in situ using scanning probe nanolithography and time-lapse atomic force microscopy (AFM). Self-assembled monolayers (SAMs) prepared from dilute solutions of multidentate thiols were found to assemble slowly, requiring more than six hours to generate films. A clean gold substrate was first imaged in ethanolic media using liquid AFM. Next, a 0.01 mM solution of multidentate thiol was injected into the liquid cell. As time progressed, molecular-level details of the surface changes at different time intervals were captured by successive AFM images. Scanning probe based nanofabrication was accomplished using protocols of nanografting and nanoshaving with n-alkanethiols and a tridentate molecule, 1,1,1-tris(mercaptomethyl)heptadecane (TMMH). Nanografted patterns of TMMH could be inscribed within n-alkanethiol SAMs; however, the molecular packing of the nanopatterns was less homogeneous compared to nanopatterns produced with monothiolates. The multidentate molecules have a more complex assembly pathway than monothiol counterparts, mediated by sequential steps of forming S–Au bonds to the substrate.

scholarly journals Development of an Enzyme-Coated Microcantilever-Based Biosensor for Specific Detection of Short-Chain Alcohols

2021 ◽  
Vol 6 (1) ◽  
pp. 75
Author(s):  
Alexandre Margarido ◽  
Livia Regina Manzine ◽  
Fernando M. Araujo-Moreira ◽  
Renato Vitalino Gonçalves ◽  
Paulo Sergio de Paula Herrmann
Keyword(s):  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Short Chain ◽  
Self Assembled Monolayers ◽  
Specific Detection ◽  
Force Microscopy ◽  
Nonpolar Solvents ◽  
Atomic Force ◽  
Assembled Monolayers ◽  
Enzymatic Detection

This paper describes the development of a biosensor designed for the enzymatic detection of short-chain alcohols. The biorecognition element, alcohol dehydrogenase, was immobilized on self-assembled monolayers deposited on top of silicon nitride microcantilevers. The self-assembly process was performed by surface activation using 3-aminopropyltriethoxysilane, followed by glutaraldehyde and biomolecule binding. X-ray photoelectron spectroscopy and atomic force microscopy were used. The biosensor showed a lower response time and sensibility from 0.03 to 1.2 mL/L. Its selectivity was analyzed through exposure to pure and mixed volatile solvents. Sensor sensibility was higher in the presence of short-chain alcohols and practically null involving other polar or nonpolar solvents.

Self-Assembled Patterning of Ultrathin Silicides by Local Oxidation

MRS Bulletin ◽  
1999 ◽  
Vol 24 (8) ◽  
pp. 31-35 ◽  
Author(s):  
S. Mantl ◽  
Q.T. Zhao ◽  
B. Kabius
Keyword(s):  
Self Assembly ◽  
Vertical Direction ◽  
Self Assembled Monolayers ◽  
X Rays ◽  
Precise Control ◽  
Spacer Layer ◽  
Local Oxidation ◽  
Assembled Monolayers ◽  
Alternative Approaches ◽  
Self Assembled

Most microfabrication techniques employ masks to transfer the desired microstructure onto a wafer using ultraviolet light, x-rays, electrons, or ions for the projection of the structures. Generally, photoresist processing and etching follow to form the final structures. In all cases, the facilities necessary to perform these processes grow increasingly more complex as the feature size of the structures diminishes, and these processes face their practical or economic limits at dimensions of about 50 nm. Thus alternative approaches are under investigation, including different self-assembly techniques. They require no costly facilities and no masks with nanometer structures, and they promise high throughput, since the patterning is directly achieved by a physical or chemical process. Self-assembled monolayers of long-chain organic molecules are the most widely studied examples, where chemisorption and spontaneous self-ordering of the molecules are observed on appropriate substrates. Another interesting example is island-ordering, laterally or in a vertical direction, during epitaxial growth. The lattice-mismatched islands tend to nucleate preferentially on top of each other when separated by a thin spacer layer, due to the associated strain field. Another approach is the use of specific stressor layers on the surface to obtain alignment of buried precipitates along the stressor lines. However, the main challenges of all self-assembly techniques are precise control of the dimensions of the structures and reproducibility.

scholarly journals STM visualisation of counterions and the effect of charges on self-assembled monolayers of macrocycles

2011 ◽  
Vol 2 ◽  
pp. 674-680 ◽  
Author(s):  
Tibor Kudernac ◽  
Natalia Shabelina ◽  
Wael Mamdouh ◽  
Sigurd Höger ◽  
Steven De Feyter
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Assembly Process ◽  
Organic Monolayers ◽  
Preferential Adsorption ◽  
Scanning Tunnelling ◽  
Assembled Monolayers ◽  
Tunnelling Microscopy ◽  
Self Assembled

Despite their importance in self-assembly processes, the influence of charged counterions on the geometry of self-assembled organic monolayers and their direct localisation within the monolayers has been given little attention. Recently, various examples of self-assembled monolayers composed of charged molecules on surfaces have been reported, but no effort has been made to prove the presence of counterions within the monolayer. Here we show that visualisation and exact localisation of counterions within self-assembled monolayers can be achieved with scanning tunnelling microscopy (STM). The presence of charges on the studied shape-persistent macrocycles is shown to have a profound effect on the self-assembly process at the liquid–solid interface. Furthermore, preferential adsorption was observed for the uncharged analogue of the macrocycle on a surface.

Formation, Characterization, Protein Resistance, and Reactivity of Cl3Si(CH2)11(OCH2CH2)3OH Self-Assembled Monolayers

2002 ◽  
Vol 724 ◽  
Author(s):  
Jiehyun Seong ◽  
Seok-Won Lee ◽  
Paul E. Laibinis
Keyword(s):  
Ethylene Glycol ◽  
Chemical Modification ◽  
Self Assembly ◽  
Protein A ◽  
Self Assembled Monolayers ◽  
Protecting Group ◽  
Protein Resistance ◽  
Attachment Sites ◽  
Assembled Monolayers ◽  
Selective Immobilization

AbstractWe report a method for generating tri(ethylene glycol)-terminated-n-alkyltrichlorosiloxane monolayers on SiO2 surfaces. These chemisorbed films, with a thickess of ∼2-3 nm, provide an oligo(ethylene glycol) surface that reduces the nonspecific adsorption of proteins and hydroxyl attachment sites for covalently immobilizing biomolecules to the substrate. These mono-molecular films were formed by adsorbing an acetoxy-tri(ethylene glycol)-terminated n-alkyltrichlorosilane, CH3(C=O)O(CH2CH2O)3(CH2)11SiCl3, onto glass and Si/SiO2 substrates, where the terminal acetate provided a protecting group for the hydroxyl functionality during self-assembly of the film. After formation of the monolayer, the acetate functionality was reduced chemically to form films exposing a covalently attached -(OCH2CH2)3OH terminus at a density of ∼3[.dotmath]1014 molecules/cm2. Protein adsorption studies verified that the films exhibited notable resistances against the non-specific adsorption of various proteins. Chemical modification of the -(OCH2CH2)3OH surface with protein A provided a non-adsorbing surface for selective immobilization of immunoglobulins.

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