Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Template-directed growth of nanostructures

Abstract:
The controlled growth and alignment of carbon nanotubes and peptide nanoarrays offers new avenues for nanodevice fabrication.

Template-directed growth of nanostructures

WA | Posted on December 1st, 2008

Creating intricate nanoelectronic devices requires the precise patterning of carbon nanotube (CNT) arrays. However, creating such complex and carefully aligned structures at nanometer scales is a difficult challenge for researchers. One fabrication approach that has attracted tremendous interest is the use of templates to control the growth patterns of nanomaterials.1-3 These templates consist of substrates on which a catalyst has been carefully patterned. Synthesis of the nanostructures is then performed on the substrate, which directs their growth and alignment.

A number of techniques, including microcontact printing, photolithography, e-beam lithography, and dip-pen nanolithography (DPN), have been used to generate such templates at both micron and nanometer scales. Among these techniques, DPN4,5 can precisely deliver catalyst materials to a specifically designated location to form any desired pattern with feature sizes as small as 100nm. DPN is an atomic force microscopy (AFM)-based technique with high resolution and registration capabilities. More important, DPN is a maskless and single-step method that can be performed without the need for high-vacuum, high-energy ions, or electron beams. Taking advantage of these characteristics, our group has been exploring novel routes for controlled growth of single-walled CNTs (SWCNTs) and peptide arrays.

We have developed a simple, efficient, and uniform AFM tip-coating method called scanning-coating6 that enables us to pattern nanoparticle (NP) arrays over a large area without recoating the tip. The coated tip can be used to generate cobalt (Co) NP dots with feature sizes of less than 70nm. Dots, lines, and even sophisticated patterns of Co NPs can be routinely generated and used as templates for controlled growth of CNTs. Figure 1(A) shows SWCNTs successfully grown on DPN-patterned Co catalyst dots positioned on silicon/silicon oxide (Si/SiOx) substrates. Furthermore, we were able to direct the growth of SWCNTs on stable temperature-cut single-crystal quartz substrates along the [100] crystallographic direction: see Figure 1(B). In addition, DPN is capable of delivering Co NPs precisely to the desired location without contaminating other regions. This offers a convenient approach for observing the growth of SWCNTs, which has provided direct proof of the base-growth mechanism for SWCNT formation observed in our experiments.6

Although peptide patterns have been previously generated using DPN on various substrates, including gold,7 nickel, Si/SiOx, and gallium arsenide, to the best of our knowledge, the in situ growth of peptide nanoarrays with carefully controlled chain lengths has not been reported. We have developed a novel route based on the combination of DPN and ring-opening polymerization (ROP) of tryptophan-N-carboxyanhydrides (Trp-NCAs) to generate peptide patterns on the nanometer scale.8 The uniqueness of this method is that the DPN-generated amine-terminated polyamidoamine (PAMAM) dendrimer nanoarray serves as the anchoring scaffold for in situ growth of the peptide array. This is achieved by immersing the patterned substrate in a Trp-NCA solution. Figure 2(A) shows the DPN-generated PAMAM dendrimer dot array on a Si/SiOx substrate. After a 6h ROP reaction, the height of the patterned dots was dramatically increased, indicating that the peptides successfully grew on the PAMAM dendrimers: see Figure 2(B). Importantly, the height (i.e., chain length) of the synthesized peptides can be controlled by varying the ROP reaction time and concentration of the Trp-NCA in solution.

In summary, we have developed novel routes for generating CNT and peptide nanopatterns on DPN-fabricated templates. The controlled patterning of CNTs provides new possibilities for making CNT-based electronics, and the controlled growth of peptide nanoarrays offers new avenues for developing biology-based applications, including the study of cell behaviors, such as adhesion, growth, and migration. We are optimizing the DPN parameters and CNT growth conditions so as to get more precise control of the density and even conductivity of CNTs. The study of cell behaviors on designed nanoarrays is ongoing in our group.

Hua Zhang acknowledges support from a Nanyang Technological University start-up grant and Academic Research Fund Tier 1 funding (RG 20/07) from the Ministry of Education in Singapore.
Bing Li, Xiaozhu Zhou, Freddy Boey, Hua Zhang
School of Materials Science and Engineering
Nanyang Technological University
Singapore, Singapore

Bing Li received his MS degree in chemistry from Nankai University in 2006. He is currently a PhD candidate under the supervision of Hua Zhang.

Xiaozhu Zhou received his BS degree in materials science from Zhejiang University in 2006. He is currently a PhD candidate working with Freddy Boey and Hua Zhang.

Freddy Boey is the chair of the School of Materials Science and Engineering at Nanyang Technological University. He has published more than 230 journal papers, 20 patents, and founded 3 companies.

Hua Zhang is an assistant professor in the School of Materials Science and Engineering at Nanyang Technological University. He has published 2 invited book chapters, more than 50 papers, and over 20 patent applications that include 2 issued US patents.
References:
1. A. L. Briseno, S. C. B. Mannsfeld, M. M. Ling, S. Liu, R. J. Tseng, C. Reese, M. E. Roberts, Y. Yang, F. Wudl, Z. Bao, Patterning organic single-crystal transistor arrays, Nature 444, pp. 913-917, 2006.doi:10.1038/nature05427
2. D. B. Weibel, W. R. DiLuzio, G. M. Whitesides, Microfabrication meets microbiology, Nat. Rev. Micro. 5, pp. 209-218, 2007.doi:10.1038/nrmicro1616
3. K. L. Christman, V. D. Enriquez-Rios, H. D. Maynard, Nanopatterning proteins and peptides, Soft Matter 2, pp. 928-939, 2006.doi:10.1039/b611000b
4. D. S. Ginger, H. Zhang, C. A. Mirkin, The evolution of dip-pen nanolithography, Angew. Chem. Int. Ed. 43, pp. 30-45, 2004.doi:10.1002/anie.200300608
5. K. Salaita, Y. Wang, C. A. Mirkin, Applications of dip-pen nanolithography, Nat. Nanotechnol. 2, pp. 145-155, 2007.doi:10.1038/nnano.2007.39
6. B. Li, C. F. Goh, X. Zhou, G. Lu, H. Tantang, C. Xue, F. Y. C. Boey, H. Zhang, Patterning colloidal metal nanoparticles for controlled growth of carbon nanotubes, Adv. Mater., in press.doi:10.1002/adma.200802306
7. Y. Cho, A. Ivanisevic, TAT peptide immobilization on gold surfaces: a comparison study with a thiolated peptide and alkylthiols using AFM, XPS, and FT-IRRAS, J. Phys. Chem. B 109, pp. 6225-6232, 2005.doi:10.1021/jp045731q
8. X. Zhou, Y. Chen, B. Li, G. Lu, F. Y. C. Boey, J. Ma, H. Zhang, Controlled growth of peptide nanoarrays on Si/SiOx substrates, Small 4, pp. 1324-1328, 2008.doi:10.1002/smll.200701267
DOI: 10.1117/2.1200810.1351

####

For more information, please click here

Copyright © SPIE

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Collaboration could lead to biodegradable computer chips May 28th, 2015

Technology for Tomorrow’s Market Opportunities and Challenges: LetiDays Grenoble Presents the Possibilities: June 24-25 Event Includes Focus on IoT-Augmented Mobility and Leti’s Latest Results on Silicon Technologies, Sensors, Health Applications and Smart Cities May 27th, 2015

Arrowhead to Present at Jefferies 2015 Healthcare Conference May 27th, 2015

Chip Technology

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Collaboration could lead to biodegradable computer chips May 28th, 2015

Technology for Tomorrow’s Market Opportunities and Challenges: LetiDays Grenoble Presents the Possibilities: June 24-25 Event Includes Focus on IoT-Augmented Mobility and Leti’s Latest Results on Silicon Technologies, Sensors, Health Applications and Smart Cities May 27th, 2015

Physicists solve quantum tunneling mystery: ANU media release: An international team of scientists studying ultrafast physics have solved a mystery of quantum mechanics, and found that quantum tunneling is an instantaneous process May 27th, 2015

Nanotubes/Buckyballs/Fullerenes

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

Researchers develop new way to manufacture nanofibers May 21st, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Cotton fibres instead of carbon nanotubes May 9th, 2015

Nanoelectronics

Technology for Tomorrow’s Market Opportunities and Challenges: LetiDays Grenoble Presents the Possibilities: June 24-25 Event Includes Focus on IoT-Augmented Mobility and Leti’s Latest Results on Silicon Technologies, Sensors, Health Applications and Smart Cities May 27th, 2015

One step closer to a single-molecule device: Columbia Engineering researchers first to create a single-molecule diode -- the ultimate in miniaturization for electronic devices -- with potential for real-world applications May 25th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Discoveries

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Collaboration could lead to biodegradable computer chips May 28th, 2015

Nanotechnology identifies brain tumor types through MRI 'virtual biopsy' in animal studies: If results are confirmed in humans, tumor cells could someday be diagnosed by MRI imaging and treated with tumor-specific IV injections; new NIH grant will fund future study May 27th, 2015

Who needs water to assemble DNA? Non-aqueous solvent supports DNA nanotechnology May 27th, 2015

Announcements

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Collaboration could lead to biodegradable computer chips May 28th, 2015

Who needs water to assemble DNA? Non-aqueous solvent supports DNA nanotechnology May 27th, 2015

Controlled Release of Anticorrosive Materials in Spot by Nanocarriers May 27th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project