Fabrication and Friction Properties of PDMS Pillars with ... · altered the sti˜ness of the...
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Results show that as stiffness increases, the friction is not affected 0 0.5 1 1.5 2 2.5 3 3.5 4 20 25 30 35 40 45 50 55 Friction, N Shore A Value 34 25.4 47.4 42.7 49.625 0 10 20 30 40 50 60 0% 5% 10% 15% 20% 25% 30% 35% Shore A Value Weight Percent of Iron (III)Oxide Made several samples with different weight percent of Iron (III) Oxide. Results Dispersed particles create a stiffer PDMS without affecting the friction force. We successfully fabricated PDMS pillars with embedded particles. Conclusions Friction Test Stiffness Test Test surface Pulley Weight = Friction Rubber Metal load (20 g) Fibrillar array Test Methods 1g PDMS 0.1 g curing agent Stir Molding on Si Template Vacuum eliminate bubbles Oven cure ~60 ℃ 2 hours PDMS X grams of Iron (III) Oxide Stir 10 µm Many people have tried to mimick the feet of geckos with soft PDMS, a type of synthetic rubber. Procedure Si PDMS Si We intend to create a stiffer PDMS by embedding Iron (III) Oxide particles in the sample Soft PDMS sticks well, but there are some mechanical stability issues: Clumping, material strength. Clumping Objective Geckos feet contain setae, which are responsible for the climbing properties of these animals. The fibrillar array conforms to the surface, which increases the Van der Waals force interaction. Normal Interface Fibrillar Interface Fabrication and Friction Properties of PDMS Pillars with Embedded Particles Manuel Leyva, Yongkwan Kim, Ye Tian, Roya Maboudian Applied Materials and Surface Science Laboratory, University of California, Berkeley Introduction Changing the amount of curing agent used for the preparation of PDMS altered the stiffness of the sample. Ratio Between PDMS and Curing Agent Durometer Reading 10 to 0.5 20.3 10 to 1.0 43.2 10 to 1.5 49.2 0 0.5 1 1.5 2 2.5 3 0 10 20 30 40 50 60 Friction, N Durometer Reading As pure PDMS becomes stiffer, the friction force decreases. Soft PDMS, a synthetic rubber known for its adhesive properties, has previously been used in an effort to mimick the feet of geckos. However, soft PDMS has mechanical stabilty issues, like clumping and material strength. By dispersing Iron (III) Oxide into the PDMS sample, the stiffness is increased while the friction force remains unaffected. Acknoledegments: National Science Foundation, Transfer-to-Excellence Research Experience for Undergraduates, Applied Materials and Surface Science Laboratory, Yongkwan Kim, Ye Tian, Roya Maboudian Future Work Confirm the dispersion of particles at micro scale. Perform reproducibility tests to decrease error bars. Test longer and thinner length fibers. Test and compare with previous work.
Transcript of Fabrication and Friction Properties of PDMS Pillars with ... · altered the sti˜ness of the...
Results show that as sti�ness increases, the friction is not a�ected
0
0.5
1
1.5
2
2.5
3
3.5
4
20 25 30 35 40 45 50 55
Fric
tion,
N
Shore A Value
34
25.4
47.4
42.7
49.625
0
10
20
30
40
50
60
0% 5% 10% 15% 20% 25% 30% 35%
Shor
e A
Val
ue
Weight Percent of Iron (III)Oxide
Made several samples with di�erent weight percent of Iron (III) Oxide.
Results
Dispersed particles create a sti�er PDMS without a�ecting the friction force.
We successfully fabricated PDMS pillars with embedded particles.
Conclusions
Friction TestSti�ness Test
Test surface
Pulley
Weight = Friction
RubberMetal load (20 g)
Fibrillar array
Test Methods
1g PDMS
0.1 g curing agent
Stir Molding on
Si Template
Vacuum
eliminatebubbles
Oven cure
~60 ℃ 2 hoursPDMS
X grams of Iron (III)
Oxide
Stir10 µm
Many people have tried to mimick the feet of geckos with soft PDMS, a type of synthetic rubber.
Procedure
Si
PDMS
Si
We intend to create a sti�er PDMS by embedding Iron (III) Oxide particles in the sample
Soft PDMS sticks well, but there are some mechanical stability issues:
Clumping, material strength.
Clumping
Objective
Geckos feet contain setae, which are responsible for the climbing properties of these animals. The �brillar array conforms to the surface, which increases the Van der Waals force interaction.
Normal Interface Fibrillar Interface
Fabrication and Friction Properties of PDMS Pillars with Embedded Particles
Manuel Leyva, Yongkwan Kim, Ye Tian, Roya MaboudianApplied Materials and Surface Science Laboratory, University of California, Berkeley
Introduction
Changing the amount of curing agent used for the preparation of PDMS altered the sti�ness of the sample.
Ratio Between PDMS and Curing Agent Durometer Reading10 to 0.5 20.310 to 1.0 43.210 to 1.5 49.2
0
0.5
1
1.5
2
2.5
3
0 10 20 30 40 50 60Fri
ctio
n, N
Durometer Reading
As pure PDMS becomes sti�er, the friction force decreases.
Soft PDMS, a synthetic rubber known for its adhesive properties, has previously been used in an e�ort to mimick the feet of geckos. However, soft PDMS has mechanical stabiltyissues, like clumping and material strength. By dispersing Iron (III) Oxide into the PDMS sample, the sti�ness is increased while the friction force remains una�ected.
Acknoledegments: National Science Foundation, Transfer-to-Excellence Research Experience for Undergraduates, Applied Materials and Surface Science Laboratory, Yongkwan Kim, Ye Tian,Roya Maboudian
Future Work
Con�rm the dispersion of particles atmicro scale.
Perform reproducibility tests to decreaseerror bars.
Test longer and thinner length �bers. Testand compare with previous work.
