YZ Adhesion Testing 2

Test Setup

• 2-axis YZ stage.
• Control loop at 250Hz.
• Attempted to improve adjustment screws on stage.
• Sampling force plate at 1000Hz.
• Positioning accuracy of +/- 25um.
• Minimum speed (stiction limit) of ~2mm/s.
• Independent control of each axis (no coupling).

Experiment #1

Procedure

• Pre-load in Z-axis by applying displacement (100um, 200um, 300um, 400um, 500um)
• Pre-load in Y-axis by applying displacement (0um, 100um, 200um, 300um, 400um, 500um)
• Pull-off at specified angle (90 = Z-axis, 0 = Y-axis) (15deg, 30deg, 45deg, 60deg, 75deg, 90deg)

Materials

• Sample - "Sangbae" directional adhesive pad
• Substrate - Acrylic

Results

• Measured maximum forces in Y and Z at pull-off

• Experiment1_PullOff.jpg:
  

Experiment #2

Procedure

• Pre-load along 45deg trajectory to Z-depth (100um, 200um, 300um, 400um, 500um, 600um, 700um, 800um, 900um, 1000um)
• Drag along Y-axis 5mm
• Pull-off at 45deg

Materials

• Sample - "Sangbae" (urethane posts with angled tips) directional adhesive pad
• Substrate - Acrylic

Results

• Measured maximum forces in Y and Z before onset of sliding
• Measured Y and Z forces during sliding
• Measured maximum forces in Y and Z at pull-off

• Experiment2_PreSliding.jpg:
  

• Experiment2_Sliding.jpg:
  

• Experiment2_PostSliding.jpg:
  

Experiment #3

Procedure

• Pre-load along 45deg trajectory to Z-depth (100um, 200um, 300um, 400um, 500um, 600um, 700um, 800um, 900um, 1000um)
• Drag along Y-axis 5mm
• Pull-off at 45deg

Materials

• Sample - "Sangbae" (urethane posts with angled tips) directional adhesive pad with Carbon Nanotubes
• Substrate - Acrylic

Results

• Measured maximum forces in Y and Z before onset of sliding
• Measured Y and Z forces during sliding
• Measured maximum forces in Y and Z at pull-off

• Experiment3_PreSliding.jpg:
  

• Experiment3_Sliding.jpg:
  

• Experiment3_PostSliding.jpg:
  

Experiment #4

Procedure

• Pre-load in Z-axis by applying displacement (100um, 200um, 300um, 400um)
• Pull-off at 90deg

Materials

• Sample - Flat-tipped cylindrical posts with carbon nanotubes
• Substrate - Acrylic

Results

• Measured maximum pre-load in Z-axis
• Measured maximum pull-off in Z-axis

• Experiment4_PullOff.jpg: