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CONTENTS
Introduction
Motivations of this Work
Block Diagram of the FBM Device
Description of the FBM Device
Cantilever Spring Constant Calibration
In Vitro Mechanical Characterization Experiments
Conclusion
References

INTRODUCTION
Mechanotransduction
Characterization of Cell Mechanical Properties
Scanning Probe Microscopy(SPM) and Advanced Robotics Approaches
Demonstration on the Epithelial Hela Cells

MOTIVATIONS OF THE WORK
SPM by Atomic Force Microscope(AFM)
Cost and Flexibility
Requires Complex Experiments and Specific Environments
Single Cell Target
Has Problems in Using Sharp tip Cantilever
Use of Tipless Cantilever and FBM System
FORCE BIO MICROSCOPE(FBM) DEVICE
Combines SPM and Advanced Robotics Approaches
Having a Tipless Catilever
Cantilever Spring Constant Calibration by Determination of Cantilever Thickness


BLOCK DIAGRAM OF THE FBM DEVICE
EXPERIMENTAL SETUP OVERVIEW
FBM is a Hybrid AFM
Has Three Units-The Mechanical Sensing Unit ,The Imaging Unit and The Clean Room In Vitro Unit
Cage Incubator is Used For Providing Suitable Condition
Force/Vision Referenced Control
Antivibration Table For Avoiding Undesired Vibrations

MECHANICAL SENSING UNIT
Performs detection , Positioning and Sensing
Sensing By Optical Technique
Four Quadrant Photodiode and Laser Diode for Measurements
Uncoated Tipless Silicon Cantilever as the Probe
3 DOF Micropositioning Stage
Use of PD Controller for Optimal Performance

CONFIGURATION OF THE MECHANICAL SENSING UNIT
IMAGING UNIT
For Imaging and Cell Tracking Features
Consists of an Inverted Microscope
Charged Coupled Device(CCD)Camera is Fitted with the Microscope
Automatic Mechanical Characterization Based on Image Feature Tracking
Calibration of the CCD Camera by Calibrated Glass Microarray and Calibrated Microspheres

CLEAN ROOM UNIT
Allows Experiments to be Conducted In a Biological Environment
Provide a Biological Nutritional Medium , Required Temperature of 37 ◦C , 5% CO2 Medium
A Controlled Heating Module Maintains the Temperature
Temperature Control is by a Configurable PID Controller

FBM EXPERIMENTAL SETUP

CANTILEVER SPRING CONSTANT CALIBRATION
Determination of Cantilever Thickness by a Dynamical Frequency Response Method For Spring Constant Calibration
Spring Constant Calibration According to the Dimensions of Cantilever

FREQUENCY RESPONSE METHOD FOR DETERMINATION OF CANTILEVER’S THICKNESS
Let us consider a cantilever of uniform section S, density ρ,Young’s modulus E, and inertial moment I. Each point of the cantilever should validate the classic wave equation for a beam in vibration, under the hypothesis of an undamped system
ρS∂2v/∂t2 + EI∂4v/∂x4 = 0 (1) where v is the instantaneos deformation of beam,depends on time and position.
v(x,t)=f(x)g(t).
to solve (1),the boundary conditions required are
v(0)=0, θ(0) = 0,M(L)=0,T(L)=0;
Contd..
The system of boundary equations accepts a solution only if the determinant is zero, which is equivalent to
1 + cos μ cosh μ = 0. (2)
With μ = (ω2(ρS/E’I))1/4αL, (2) gives one condition on μ to be respected, which defines the eigenfrequency of the system
from the above conditions the mean value of cantilever thickness is given by
N
<h>=1/N∑ ωi L2 /μi2√ 12ρ/ E’
i=1 with N being the number of the measured eigenfrequency.

CANTILEVER SPRING CONSTANT DETERMINATIN BY STATIC METHOD
From the dimensions of the cantilever the spring constant of the cantilever
k=3EI/L³
where I=lh³/12, the moment of inertia
This Method has High Accuracy
IN VITRO MECHANICAL CHARACTERIZATION EXPERIMENTS
EpH Cells are Prepared on Petri Dishes
The Samples are of Dimension 10Цm*9Цm*6Цm
CELL’S MECHANICAL RESPONSE CHARACTERISATION
Photodiode o/p vs sample vertical displacement on EpH cell and a Hard surface
The deformation δ is the difference of Δz and Δd
The non linear elastic behaviour of EpH is
found
Viscoelastic behaviour of EpH cell is also investigated

Contd..
VISCOELASTIC BEHAVIOUR
IN VITRO EFFICIENCY APPROACH
To find the efficiency of the clean room unit
Perform automatic and cyclical spectroscopy operation with and without incubating system
Mechanical Characterization is temperature dependant


CONCLUSION
Presented a Microforce Sensing System for in vitro Mechanotransduction Investigation
Reliable and Effective Mechanical Characterisation and Data Acquisition Can be Achieved
Experiments on EpH Cells by FBM Demonstrated the Efficiency of the Setup