Method of and apparatus for studying fast dynamical mechanical response of soft materials

Abstract

The invention is an apparatus and method including hardware and software, which allows collecting and analyzing data to obtain information about mechanical properties of soft materials in a much faster way. The apparatus can be used as a stand-alone deice or an add-on to the existing AFM device. The apparatus allows collecting dynamical measurements using a set of multiple frequencies of interest at once, in one measurement instead of sequential, one frequency in a time; measurements.

1. A device comprising:
 performing a fast dynamical mechanical response of soft materials further comprising: 
 an atomic force microscope scanner having a cantilever and a probe; 
 a computer programmed to provide said AC signals and said a DC offset voltage; 
 said AC signals coupled to a first input of said a summing device; 
 said DC offset voltage coupled to a second input of said summing device; 
 said summing device provides said AC signals and said DC offset voltage to said atomic force microscope access box and a first input of a computer via a data acquisition card; 
 said access box provides said summed signal is coupled to an input of said atomic force microscope scanner; 
 said access box receives an output signal from said atomic force microscope scanner; 
 saidan output signal is coupled to a second input of said computer from said atomic force microscope access box via said data acquisition card; 
 said computer programmed to conduct an analysis of data from said summation device and said atomic force microscope scanner, wherein said program conducts a Fast Fourier Transform analysis of said data. 
 
     
     
       2. The apparatus of  claim 1  wherein said analysis is completed in a time of less than 1.5 hours. 
     
     
       3. The apparatus of  claim 1  wherein said AC signals further comprise a plurality of frequencies between 1000 0.001 Hz and 100 tens of MHz. 
     
     
       4. The apparatus of  claim 1  wherein an amplitude of said AC signals is sufficiently small to avoid cross-talk (non-linear response) between signals of different frequencies. 
     
     
       5. The apparatus of  claim 1  wherein said DC offset voltage ranges from zero to a voltage required to produce a deflection of said scanner being used to make deformation of interest relative to a sample being studied. 
     
     
       6. The apparatus of  claim 1  wherein said probe is a photo detector. 
     
     
       7. The apparatus of  claim 1  wherein said analysis includes the study of fast changes in viscoelastic properties of materials such as biological materials, reactive soft materials, or polymers. 
     
     
       8. An apparatus comprising:
 providing input signals to and receiving from an output signal from an external atomic force microscope scanner for performing a fast dynamical mechanical response analysis of soft materials further comprising: 
 a computer programmed to provide said AC signals and said a DC offset voltage; 
 said AC signals are coupled to a first input of a summing device; 
 said DC offset voltage is coupled to a second input of said summing device; 
 said summing device provides said AC signals and said DC offset voltage to said atomic force microscope access box and a first input of a computer via a first data acquisition card; 
 said access box provides summed signal is coupled to an input of said external atomic force microscope scanner; 
 said access box receives an output signal from said external atomic force microscope scanner; 
 saidan output signal from said atomic force microscope scanner is coupled to a second input of said computer from said atomic force microscope access box via a second data acquisition card; 
 said computer programmed to conduct an analysis of data from said summation device and said external atomic force microscope scanner, wherein said program conducts a Fast Fourier Transform analysis of said data. 
 
     
     
       9. The apparatus of  claim 8  wherein said analysis is completed in a time of less than 1.5 hours. 
     
     
       10. The apparatus of  claim 8  wherein said signals comprise a plurality of frequencies between 1000 0.001 Hz and 100 tens of MHz. 
     
     
       11. The apparatus of  claim 8  wherein an amplitude of said AC signals are sufficiently small to avoid cross-talk (non-linear response) between signals of different frequencies. 
     
     
       12. The apparatus of  claim 8  wherein said DC offset voltage ranges from zero to a voltage required to produce a deflection of said scanner being used to make deformation of interest to sample being studied. 
     
     
       13. The apparatus of  claim 8  wherein said analysis includes the study of fast changes in viscoelastic properties of materials such as biological materials, reactive soft materials, or polymers. 
     
     
       14. A method comprising:
 performing a fast dynamical mechanical response of soft materials further comprising: 
 generating a plurality of AC signals; 
 generating a variable DC offset voltage; 
 summing said plurality of AC signals and said DC offset voltage; 
 coupling said summed signal to an input of an atomic force microscope scanner and to an input of a data acquisition card; 
 using a cantilever and probe portion of said scanner to measure a sample; coupling an output of said probe to a second input of said data acquisition card; 
 coupling a first output of said data acquisition card representing said input signal to said scanner to a first input of said computer; 
 coupling a second output of said data acquisition card representing said output signal of said scanner to a second input of said computer; 
 performing a fast Fourier transform analysis of said sample using said input signal and said output signal. 
 
     
     
       15. The method of  claim 14  wherein said analysis is completed in a time of less than 1.5 hours. 
     
     
       16. The method of  claim 14  wherein said signals comprise a plurality of frequencies between 1000 0.001 Hz and 100 tens of MHz. 
     
     
       17. The method of  claim 14  wherein an amplitude of said AC signals are sufficiently small to avoid cross-talk (non-linear response) between signals of different frequencies. 
     
     
       18. The method of  claim 14  wherein said DC offset voltage ranges from zero to a voltage required to produce a deflection of said scanner being used to make deformation of interest to sample being studied. 
     
     
       19. The method of  claim 14  wherein said analysis includes the study of fast changes in viscoelastic properties of materials such as biological materials, reactive soil materials, or polymers. 
     
     
       20. The apparatus of claim 3, wherein said AC signals further comprise a plurality of frequencies between 5 Hz and 300 Hz. 
     
     
       21. The apparatus of claim 10, wherein said AC signals further comprise a plurality of frequencies between 5 Hz and 300 Hz. 
     
     
       22. The apparatus of claim 16, wherein said AC signals further comprise a plurality of frequencies between 5 Hz and 300 Hz.