Probe Sharpening

Probes can be sharpened to increase their ability to penetrate tissue without "dimpling", i.e. without putting pressure on the tissue, which may cause decreased recording quality.

Method 1: With a patch pipette sharpener

recommended sharpener: EG-401

1. Move the micropositioner z-axis to the top of its range and orient the probe mount horizontally.
2. Attach the probe to the micropositioner using probe mount adapter of your choice and set the probe angle between 15-25 degrees, keeping the probe well above the abrasive surface.
3. Slowly lower the probe until 1mm above the abrasive surface and bring into focus through microscope objective
4. Adjust wheel speed to 2000 rpm
5. Lower the probe to make contact with the polishing wheel surface.
6. After making contact with the surface, advance the micropositioner another roughly 500 microns. The silicon probe shank will bend, providing force to advance the tip as material is removed.
7. Observe the tip during the grinding process, stopping once the front edge is sharp. The speed of the grinding will slow as additional material is removed and the cross sectional area of the polished surface increases. The whole process should take between 5-10 minutes and is relatively insensitive to precise timing.

Method 2: With a modified hard drive

Example hard drive modification

Abrasive polishing disks: Krell Tech, Part No: PF00.XW-P-4 Final Polish film, PSA, 4 inch self-adhesive pad Link