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A haptic device is used as real-time 3-D force feedback and command input of AFM tip position. The real-time visual display includes a live image of cantilever tip from the charge coupled device (CCD) camera and a dynamic AFM image of the operating environment, which is locally updated based on realtime force information.
Source publication
Due to the unique electrical properties of carbon nanotube (CNT), CNT is often chosen as a building block for nanosystems or nanodevice. The most challenging part in fabricating nanosystems could be the formation of CNT connections. Existing techniques in forming CNT connections, such as dielectrophoresis, direct growth, E-beam lithography and self...
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... these manipulation schemes is the lack of real-time visual feedback. Each operation has to be verified by another new image scan before the next operation. Obviously, this scan-design-manipulation-scan cycle is time consuming and less accurate. We have developed an AFM based nano robotic system assisted by augmented reality in our lab as shown in Fig. 1. It includes three subsystems: the AFM system (Bioscope, manufactured by Veeco Instruments Inc.), the control system and the human interface enhanced by augmented reality. The Bioscope system is equipped with a closed-loop scanning head (Veeco Instruments Inc.). Peripheral devices include an optical microscope and a charge-coupled ...
Citations
... Sensor design by placing a monolayer graphene between the electrodes in lateral configuration is difficult and an expensive task, since it requires high-end nanoscale manipulation techniques 24 . Other disadvantage is its less absorption area, which in turn limits the responsivity of sensor. ...
We report a facile and cost-effective approach to develop self-standing reduced Graphene Oxide (rGO) film based optical sensor and its low-temperature performance analysis where midgap defect states play a key role in tuning the crucial sensor parameters. Graphite oxide (GO) is produced by modified Hummers' method and reduced thermally at 250 °C for 1 h in Argon atmosphere to obtain rGO. Self-standing rGO film is prepared via vacuum filtration. The developed film is characterized by HRTEM, FESEM, Raman, and XRD techniques. The developed sensor exhibits highest sensitivity towards 635 nm illumination wavelength, irrespective of the operating temperature. For a given excitation wavelength, photoresponse study at low temperature (123K-303K) reveals inverse relationship between sensitivity and operating temperature. Highest sensitivity of 49.2% is obtained at 123 K for 635 nm laser at power density of 1.4 mW/mm2. Unlike sensitivity, response- and recovery-time demonstrate directly proportional dependence with operating temperature. Power dependent studies establish linear relation between power-density and sensitivity, and a safe limit beyond which sample heating prolongs the recovery time. Wavelength-dependent studies shows that proposed sensor can efficiently operate from visible to near NIR region. To the best of our knowledge such rGO based optical sensor performance at low temperature had not been reported earlier.
In this work, a simple low-cost technique is presented to fabricate reduced graphene oxide (rGO)-based near infrared photodetectors using vitamin C (ascorbic acid) as a reduction agent. Different levels of reduction can be obtained by varying the number of reduction cycles. The current-voltage characteristics of the fabricated rGO show excellent sensitivity towards the illumination of a continuous-wave laser. It is shown that the electrical conductivity of the devices is tailored based on the reduction level, resulting in highly enhanced conductivity. The large enhancement factors are measured for the values of photoresponsivity of the rGO at a higher reduction level.
Carbon nanotube transistor with bottom gate fabricated by atomic force microscopy based nanomanipulation system is presented in this paper. This process consists of fabrication of transistor chips using conventional optical lithography and nanoassembly of CNTs on the chips. It is found that the contact resistance between the CNT and Palladium electrodes can be as low as several hundred kΩ. By using this fabrication technique, high fabrication yield of CNT devices can be achieved. In addition, Polyimide serves as the dielectric layer and the packaging material of the transistor which allows us to modify transistor characteristic, because the Fermi level of CNTs shifted after annealing under vacuum. At low temperature, the polyimide has lower gas permeability and thereby, seals the CNT transistors.
The use of nanomaterials in nanotechnological applications, and developments in nanoscale manipulation and assembly, are discussed. There are many nanoscale materials with unique mechanical, electrical, optical, and chemical properties which have a variety of potential applications in nanodevices, nanosensors, and nanoelectromechanical systems (NEMS). The ability to manipulate the nanomaterials in a controllable manner is very critical to make these nanomaterials useful in nanotechnology. Nanomanipulation and nanoassembly are one of the important challenges in realizing the miniaturization of devices and machines potentially down to atomic and molecular sizes. The development of an automated microspotting system for rapid dielectrophoretic fabrication of bundled carbon nanotube sensors, provides a new method for using microfluidic and dielectrophoretic forces for nanoassembly.
