ELECTRICAL AND ELECTROMECHANICAL PROPERTIES OF WS2 NANOTUBES
Roi Levi1, Jonathan Garel1, David Teich2, Gotthard Seifert2, Reshef Tenne1, Ernesto Joselevich1
1 Department of Materials and Interfaces; Weizmann Institute of Science
2 Technische Universität Dresden; Theoretische Chemie
Electrical and electromechanical properties of WS2 nanotubes
Roi Levi, Materials and Interfaces Department, Weizmann Institute of Science, Israel
Jonathan Garel, Materials and Interfaces Department, Weizmann Institute of Science, Israel
David Teich, Theoretische Chemie, Technische Universität Dresden, Germany
Gotthard Seifert, Theoretische Chemie, Technische Universität Dresden, Germany
Reshef Tenne, Materials and Interfaces Department, Weizmann Institute of Science, Israel
Ernesto Joselevich, Materials and Interfaces Department, Weizmann Institute of Science, Israel
The use of nanostructures such as nanotubes and 2D sheets in electrical and electromechanical devices is the subject of intensive research in recent years. In particular, the electronic properties of inorganic compounds such as the dichlcogenides sparked the research of their incorporation into nano-electro-mechanical systems (NEMS). WS2 nanotubes (INT-WS2) have been shown to exhibit superior mechanical properties and interesting stick-slip mechanical phenomena1 and thus are a natural candidate for electro-mechanical devices.
We show here that INT-WS2 possess significant field-effect mobility and surprisingly high current carrying capacity2. We further present the first demonstration of a significant electro-mechanical response in pure inorganic nanotubes3. The INT-WS2 exhibited a highly repeatable increase of the conductivity in response to strain and/or torsion. These results are in qualitative agreement with the theoretical calculations presented here for torsion and strain. The large sensitivity to torsion and tension suggests INT-WS2 as promising in NEMS such as nano-gyroscopes and accelerometers.
Figure 1. a. Schematics of a WS2 nanotube-based torsional nano-electro-mechanical system (NEMS) and the atomic force microscope (AFM) tip used to perform the torsion. b. INT-WS2-NEMS electrical response to torsion – change in conductivity with the torsion angle. Inset – AFM image of the INT-WS2-NEMS.
(1) Nagapriya, K. S.; Goldbart, O.; Kaplan-Ashiri, I.; Seifert, G.; Tenne, R.; Joselevich, E. Physical Review Letters 2008, 101, 195501.
(2) Levi, R.; Bitton, O.; Leitus, G.; Tenne, R.; Joselevich, E. Nano Letters 2013, 13, 3736-3741.
(3) Levi, R.; Garel, J.;Teich, D.; Seifert, G.; Tenne, R.; Joselevich, E. ACS Nano 2015, Article ASAP.
 MULTI-LEGGED DNA-BASED MOLECULAR MOTORS
Yaron Berger1, Toma Tomov2, Roman Tsukanov3, Miran Liber2, Eyal Nir2
1 Ben-Gurion University; Ilse Katz Institute for Nanoscale Science & Technology
2 Ben-Gurion University of the Negev; Ilse Katz Institute for Nanoscale Science & Technology
3 Ben Gurion University; Ilse Katz Institute for Nanoscale Science & Technology
Multi-Legged DNA-Based Molecular Motors
Yaron Berger, Toma E. Tomov, Roman Tsukanov, Miran Liber and Eyal Nir
Department of Chemistry, Ben-Gurion University of the Negev, Be’er-Sheva, Israel
Natural molecular machines, made of proteins, play a major role in many important biological processes, often with impressive operational yields and speeds. Inspired by biological bipedal motors such as kinesin and with the assistance of single-molecule fluorescence and computer controlled microfluidic device we designed and operated a DNA-based bipedal motor that can stride on a DNA origami track with high operational yield. The reaction yield was 98% per step, which results in overall operational yield of 50% for 36 steps. To the best of our knowledge, this is the highest operational yield achieved by artificial molecular motors so far; however, it is not sufficient for repeatable operation of molecular machines for technological usage, for example, such as molecular assembly line and efficient maneuvering and manipulation of guest molecules.
This work focuses on the effort to understand the reasons for the 5-10% walker dissociation, and to increase walker processivity, operational yield and speed. To achieve a basic understanding of the motor’s limiting factors, kinetic measurements were made for the different reactions that make up a step, resulting with empiric reaction rates. We later built a kinetic numeric simulation to describe the correlation between each reaction rate and the final stepping yield. One possible solution for the walker dissociation is the multi-leg and multi-foothold approach, in which the walker consists of two pairs of legs and the track consist two rows of footholds. Preliminary results show an increase in yield per reaction of about two times, when operated 10uM fuel concentration. The walker, which consists of four legs, was prepared using “click” chemistry, and the motor, operated by microfluidics, was evaluated using single-molecule fluorescence
Jonathan Jeffet1, Victor Garcia-Lopez2, James M. Tour3, Yuval Ebenstein4
1 Raymond and Beverly Sackler Faculty of Exact Sciences; Tel Aviv University
2 Angel Marti Research Group; Dept. of Chemistry, Rice University
3 Rice University; Smalley Institute for Nanoscale Science & Technology
4 School of Chemistry; Tel Aviv University
Jonathan Jeffet1, Víctor García-López 2, James M. Tour2 & Yuval Ebenstein1
1Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv
2Department of Chemistry, Rice University, Texas
Molecular motors in the single nano meter scale have not yet been observed to generate propulsion. We utilize single molecule imaging of fluorescent submersible nano machines, in order to assess whether or not sufficient amount of work could be exerted by the motor to propel the nano machine and overcome the dominant viscosity forces in this extremely low Reynolds number regime.
In order to accomplish this goal, the nano machines are imaged inside silicon nano channels with a 45 nm cross section, that serve as “nano-tracks” confining the diffusion of the machines in one dimension. The nano machines contain conjugated fluorescent molecules that allow tracking their position when excited with a 637nm laser. The nano machines’ motors are activated by a UV laser generating rotation of a molecular rotor. The trajectories of the machines inside the nano channels are then analyzed and via the measurement of mean squared displacement we aim to assess the diffusion differences between activated and non-activated molecules. Thus, we wish to estimate the work done by the motor and confirm its effectiveness.
AN INNOVATIVE APPROACH TO MULTI GAS DETECTION AND PRESSURE MEASUREMENTS:NANO TECHNOLOGIES AND MECHANICS FOR A NOVEL GENERATION OF MINIATURE, MECHATRONIC ANALYTICAL INSTRUMENTS AND WIDE RANGE, ON CHIP PRESSURE DEVICE
Raffaele Correale, Gianpiero Mensa, Valter Maccantelli
NanoTech Analysis s.r.l.s
Corso Re Umberto, 65
10121 Torino, Italy
NanoTech Analysis strategic intent is to realize a new generation of proprietary, universal and ultra-simplified instruments to perform pressure and chemical measurements offering at the same time enormous state of art analytical systems simplification.
In fact, the combination of recent developments in the field of micro- and nanotechnologies (MEMS and NEMS) with technologies for chemical analysis and fluid dynamic measurements changes fundamentally the manner in which these measurements could be performed.
With that respect, creating specific synergies and leveraging on these smart combinations, NTA gives origin to an innovative new generation of instruments employing MEMS and NEMS developments to bring the measurements to the level of miniaturization.
NTA future portfolio of products and proprietary technology have been protected via a series of eight patents. Our instruments derive from two technological and completely innovative platforms. The first one relies on a universal, miniaturized (even on-chip) single pressure sensor device covering more than 18 orders of magnitude in pressure and able to identify any gas in its operating range.
The second platform gives origin to a new generation of miniature, mechatronic analytical instruments able to measure any volatile compounds in any environment processing at molecular level the minimum possible number of molecules.
Therefore, main purposes are to present NTA feasibility studies as well as original and innovative instruments layouts. In addition, same experimental set up and measurements will be presented as well. Moreover, extremely relevant appears to be the impact of our technology and products (above all in the domain of miniature and portable multi gas analyzer) when applied in domains as Defense and homeland security, Aerospace, automotive fields, environmental applications and some bio medical applications.
In fact, the baseline idea is to challenge in the smartest way the MEMS and NEMS Semiconductors Industry to realize complex Electro Mechanical Analogical devices and instrumentation (Mechatronic).
Therefore, smart miniaturization becomes for NTA an enabling factor to definitively allow unmet devices’ performances, simplify potential OEM systems, optimize operations, allow unpredictable integration potential into several different domain and applications.
 E.g. pressure measurements and standard gas analyzers.
 WIPO – PCT filings.
 E.g. from 10-13 mbar to >104 mbar.