FORCETOOL

Multipurpose Force Tool for Quantitative Nanoscale Analysis and Manipulation of Biomolecular, Polymeric and Heterogeneous Materials

Achievements

Progress has been made in the two pillars of ForceTool, the development the bi-modal AFM operation and the development of  a flexible, robust and  multimaterial methodology. 

Bimodal AFM. We have designed, manufactured and tested several bi-modal AFM excitation/detection prototypes.  The new AFM have successfully imaged proteins (antibodies) in air and liquid environments. We have extensively characterized the performance of the instrument under different excitation forces (mechanical and electrostatic), cantilever types, and different samples, such as biomolecules, polymers and layered materials. The force sensitivity of the instrument is about 0.2 pN, i.e., a factor 10 better than conventional tapping mode AFM.. We have demonstrated that the bimodal AFM concept is compatible with existing AFMs and with nanotomography methods. A multiscale theoretical approach have been applied to understand bimodal AFM operation. This approach has involved continuous modeling, finite element simulations and analytical approaches. The analytical model identifies the virial and the energy dissipated by the tip-surface forces as the parameters responsible for the material contrast. The agreement obtained among the theory, experiments and numerical simulations validates the model. 

We have also demonstrated that monomodal operation at higher modes and/or harmonics renders high resolution images of biological membranes and virus capsids in liquids. We have also shown that higher harmonics imaging is also compatible with molecular recognition process.
 
Multimaterial Methodology.  We have developed a method to identify the mechanism of energy dissipation at the nanoscale.  The method requires the determination of the energy dissipated on the sample surface as a function of the oscillation amplitude while the tip approaches the surface. The representation of the dissipated energy and, in particular, its derivative with respect to the amplitude, dynamic-dissipation curves hereafter, characterizes the dissipation process. Three different nonconservative processes were studied: surface energy hysteresis, viscoelasticity and long-range dissipative interfacial interactions. The method is being applied to characterize the organization of thin polymer films.

Multiscale theoretical simulations have also provided insight into the relationship between forces, molecular re-orientations and energy dissipation processes. We have performed a combined experimental and multiscale theoretical approach to establish the atomistic origins and hence the contrast, of the dissipative processes occurring in phase-imaging. First-principle simulations show that the configuration space sampled by the tip depends on whether the tip approaches or withdraws from the surface.  The quantitative agreement obtained between simulations and experiments demonstrates that the above asymmetry is the origin of the observed contrast. The asymmetry arises because the presence of energy barriers among different bonding configurations. 

Expected Impact

FORCETOOL has developed a multipurpose tool for quantitative nanoscale analysis, manipulation and morphological characterisation of polymers, biomolecules and heterogeneous surfaces in general. The instrument requires both a new concept in advanced scanning probe microscopy methods (the bi-modal AFM) and a new methodology to transform dynamic force microscopy  measurements into material properties (multimaterial methodology). Breakthroughs in FORCETOOL will primarily contribute to establish an European technological sector in the manufacturing of advanced tools for high resolution imaging and manipulation at the nanoscale. Furthermore, FT multidisciplinar approach will contribute to develop a general platform for addressing scientific and technological issues at the nanoscale in fields as diverse as coatings manufacturing, biosensors   applications (health) or new manufacturing processes based on organics (organic electronics).

 Publishable results
Patent Applications

·  Método de utilización de un microscopio de fuerzas atómicas y microscopio, R. García and Tomás R. Rodríguez, PCT/ES2006/070016. Currently under commercial exploitation.

· Método para aumentar la sensibilidad de sistemas micro y nanomecánicos con excitación multimodal, R. Garcia, J.R. Lozano, N.F. Martinez, S. Patil, PCT/ES2006/070096. Currently under commercial exploitation.

Peer Review Publications

a). FT  direct
· J.R. Lozano and R. Garcia, Theory of multifrequency AFM, Phys. Rev. Lett. 100, 076102 (2008) .
·C. Dietz, R. Magerle et al., Nanotomography with enhanced resolution using bimodal atomic force microscopy, Appl. Phys. Lett. 92, 143107 (2008).
· N. F. Martínez, J.R. Lozano, E.T. Herruzo, F. Garcia,  C. Richter, T. Sulzbach and R.Garcia, Bimodal atomic force microscopy imaging of isolated antibodies in air and liquids, Nanotechnology (in press) (2008)
·M. Bauer, A.M. Gigler, C. Richter, R.W. Stark: "Visualizing stress in silicon microcantilevers using scanning confocal Raman spectroscopy", Microelectron. Eng., in press
·S. Patil, N.F. Martinez, J.R. Lozano, R. Garcia, Force microscopy imaging of individual protein molecules with femto Newton force sensitivity, J. Mol. Recognit. 20, 516-523 (2007)
·J. Preiner, J. Tang, V. Pastushenko, and P. hinterdorfer, Higher harmonic AFM: Imaging of biological membranes in liquid, Phys. Rev. Lett. 99, 046102 (2007).
· R. Garcia, R. Magerle, R. Perez , Nanoscale imaging with gentle forces, Nature Materials  6, 405 (2007)
·R. Vázquez, F.J. Rubio-Sierra, R.W. Stark,  Multimodal analysis of force spectroscopy based on a transfer function study of micro-cantilevers, Nanotechnology, 18,  185504 (2007)
· R. W. Stark, N. Naujoks, A. Stemmer, Multifrequency electrostatic force microscopy in the repulsive regime, Nanotechnology  18, 065502 (2007)
 · F. J. Rubio-Sierra, R. Vazquez,and R. W. Stark, "Transfer Function Analysis of the Micro Cantilever used in Atomic Force Microscopy", IEEE T. Nanotechnology  5,  692-700 (2006)
· R. Garcia, C.J. Gomez, N.F. Martinez, S. Patil, C. Dietz, R. Magerle, Identification of nanoscale dissipation processes by dynamic atomic force microscopy, Phys. Rev. Lett. 97, 016103 (2006).
· N.F. Martinez, S. Patil, J.R. Lozano and R. Garcia, Enhanced compositional sensitivity in AFM by the excitation of the first two flexural modes, Appl. Phys. Lett. 89, 153115 (2006).
· N.F. Martinez and R. Garcia, Measuring phase shifts and energy dissipation with amplitude modulation AFM, Nanotechnology 17, S167 ( 2006).
 
b). FT related

·V. Palermo, A. Liscio, M. Palma, M. Surin, R. Lazzaroni, P. Samori, Chemical Communications, 3326 (2007).
·G. De Luca, A. Liscio, P. Maccagnani, F. Nolde, V. Palermo, K. Mullen, P. Samori, Advanced Functional Materials 17, 3791 (2007).
·P. Stoliar, R. Kshirsagar, M. Massi, P. Annibale, C. Albonetti, D. M. de Leeuw, F. Biscarini, Journal of the American Chemical Society  129, 6477 (2007).
·A. Liscio, G. De Luca, F. Nolde, V. Palermo, K. Müllen, P. Samorì, J. Am. Chem. Soc. 130, 780-781 (2008).
·J.M. Mativetsky, M. Palma, P. Samorì* “Exploring Electronic Transport in Molecular Junctions by Conducting Atomic Force Microscopy”, Topics in Current Chemistry  2008
·A. Liscio, V. Palermo, P. Samorì “Probing local surface potential of quasi-one-dimensional systems: a KPFM study of P3HT nanofibers”, Adv. Funct. Mater., 2008 in print
· C. Dietz, S. Röper, S. Scherdel, A. Bernstein, N. Rehse, and R. Magerle, Automatization of nanotomography, Review of Scientific Instruments 78, 053703 (2007)
.· Yoshiaki Sugimoto, Pavel Jelinek, Pablo Pou, Masayuki Abe, Seizo Morita, Rubén Pérez, and  Oscar Custance, Mechanism for Room-Temperature Single-Atom Lateral Manipulations on Semiconductors using Dynamic Force Microscopy, Phys. Rev. Lett.  98, 106104 (2007)
·Yoshiaki Sugimoto, Pablo Pou, Masayuki Abe, Pavel Jelinek, Rubén Pérez, Seizo Morita, and  Oscar Custance, Chemical identification of individual surface atoms by atomic force microscopy , Nature 446, 64 (2007)
· Scanning Probe Microscopy investigation of self-organized perylenetetracarboxdiimide nanostructures at surfaces: structural and electronic properties”.V. Palermo, A. Liscio, D. Gentilini, F. Nolde, K. Müllen, P. Samorì. Small  3, 161-167 (2007);
· Kelvin Probe Force Microscopy study of surface charges photogeneration in all-thiophene photovoltaic blends. V. Palermo, G. Ridolfi, A.M. Talarico, L. Favaretto, G. Barbarella, N. Camaioni, P. Samorí, Adv. Func. Mate. 17, 472 (2007).  
· Quantitative measurement of the local surface potential of p-conjugated nanostructures: a Kelvin Probe Force Microscopy study. Andrea Liscio, Vincenzo Palermo, Desireè Gentilini, Fabian Nolde, Klaus Müllen, Paolo Samorì,  Advanced Functional Materials 16, 1407 – 1416 (2006)
·  Scanning Force Microscopy on Molecular Nanostructures: Morphology, Properties and Nanofabrication (in italian).Cristiano Albonetti, Massimiliano Cavallini, Rajendra Kshirsagar, Fabio Biscarini “Microscopy in Italy”
· Electronic Characterization of Organic Thin Films by Kelvin Probe Force Microscopy. V. Palermo, M. Palma, P. Samori,  Advanced Materials 18, 145 (2006).
· Single atomic contact adhesion and dissipation in dynamic force microscopy, N. Oyabu, P. Pou, Y. Sugimoto, P. Jelinek, M. Abe, S. Morita and R. Perez, Phys. Rev. Lett. 92, 106101 ( 2006)
·V. Palermo, S. Morelli , M. Palma, C. Simpson, F. Nolde, A. Herrmann, K. Müllen, P. Samorì, Nanoscale phase segregated supramolecular blends of a functionalized perylene-bis-dicarboximide and an all-benzenoid polycyclic aromatic hydrocarbon: architectures for organic solar cells. ChemPhysChem.  7, 847 (2006)