This document discusses a project analyzing and simulating C-section micro cantilevers used in MEMS applications. A micro cantilever was modeled in ANSYS and its deflection calculated both analytically using Stoney's equation and through simulation. The results from both methods were compared and found to have a maximum error of 10%, validating the analytical and simulation methods. Micro cantilevers have various applications as temperature, viscosity, and biosensors due to their sensitivity depending on deflection and stress.

1. SRI KALAHASTEESWARA INSTITUTE OF TECHNOLOGY
SKIT Road, Panagal, SRIKALAHASTI -517640, Chittoor Dist
(Approved by A.I.C.T.E., New Delhi & Affiliated to JNTU, Anantapur)
Department Of Mechanical Engineering,
Project on ANALYTICAL AND SIMULATION ANALYSIS OF C-SECTION
MICRO CANTILEVERS USED IN MEMS APPLICATIONS , under the
guidance of Sri. C.VIJAYA BHASKAR REDDY
M.Tech,; M.I.S.T.E,; (Ph.D),
Assistant Professor (Sr)
C.RAJA SEKHAR 08381A0339
S.RADHA KRISHNA 08381A0338
G.V.R.TEJA 08381A0356
R.ADITYA 08381A0301
V.NITHIN KRISHNA 08381A0333
BY

2. • We are very thankful to Our beloved Principal and HOD of
Mechanical Engg Dr.B.Jayachandraiah Garu for giving us the
opportunity to do our main project
• We are also thankful to our Incharge HOD Sri.C.Bhaskar Reddy for
giving us permission in doing the project
• We express our gratitude to our Guide Sri.C.Vijaya Bhaskar Reddy
for encouraging and giving timely suggestion in completing the
project.
• We are thankful to our Non Teaching staff of mechanical
department for their co-operation during the project work.
• We dedicates this work to our Parents and teachers who imparted the
knowledge.

3. • Micro cantilevers are the most simplified MEMS
based devices
• The overall sensitivity of micro cantilever
depends on both the deflection and stress of the
cantilever
• The stress and deflection is being found by
Stoney equation analytically and simulated in
ansys software
• values are being compared and the errors are
being found.

4. • A micro cantilever is a device that can act as a
physical, chemical or biological sensor by detecting
changes in cantilever bending or vibrational
frequency. The polymer su8 is used in this project
• Micro cantilevers are a million times smaller than the
diving board having dimensions in microns (Micro=
10-6 m)

5. • In Micro Electro Mechanical Systems (MEMS)
• Temperature Sensors / Heat Sensors
• Viscosity Sensors
• In physical, chemical and biological sensing

6. • Christiane Ziegler, (2004) explains about the cantilevers based
bio-sensors. He explains mainly about the theory of cantilevers
biosensors. The most common method to measure the deflection
of a cantilever is the optical lever technique
• Mo Yang et al, (2003) describes about the High sensitivity
piezoresistive cantilever design and optimization for analyte-
receptor binding.
• Mohd. Zahid Ansari et al(2008) explains about the Study on
Increasing Sensitivity of RectangularMicrocantilevers Used in
Biosensors. He calculated the deflections using Stoney equation

7. • Stoney equation is the main basis for the
calculation of deflection in micro cantilevers
• The Stoney equation used for the calculation
of deflection is [Mohd. Zahid Ansari et al(2008) ]

8. Case-1:
polymer - su8
Pressure = 0.01 N/mm2
Surface stress ( ) = 0.8 N/m
Elastic Modulus (E) = 5Gpa
Poisson ratio (v) = 0.22
Length (l) = 200µm
Width (w) = 120µm
Thickness (t) = 2.8µm
Area (a) = 17600µm2

9. •
= 0.37µm
Deflection (Z) =0.37µm
IN SIMILAR WAY THE DEFLECTION IS BEING FOUND FOR DIFFERENT VALUES OF STRESS

10. • The software used for the analysis of
deflections in cantilevers is “ANSYS”.
• ANSYS is general-purpose finite element
analysis (FEA) software package.
• This type of analysis is typically used for the
design and optimization of a system for too
complex to analyze by hand

13. • By using Ansys the deflections have been found for
different values of Surface stress
• Case 1:
DMX= 0.479E-06

14. Case-2: Case-3:
Case-4:

15. DMX=.766E-06
SMN=58904
SMX=.912E+07

16. DMX=.766E-06
SMN=57359
SMX=.105E+08

17. Pressure (p)
N/mm2
Surface Stress(∆σ)
N/m
Simulation
deflection(µm)
Analytical
Deflection(µm)
Error (µm)
0.01 0.8 0.42 0.37 0.05
0.012 1.05 0.57 0.5 0.07
0.013 1.14 0.62 0.54 0.08
0.014 1.2 0.67 0.59 0.08
0.015 1.3 0.70 0.61 0.09

18. • The deflection of the C shaped Micro cantilever
was Calculated using Stoney’s equation
mathematically and the same cantilever is
(analyzed) simulated using Ansys software.
• Since von mises stress is less than stress
intensity the model is in safe zone
• The results shows that the analysis with
mathematical and simulated are with in a
minimum error of .1 (10%) at an approval.