Prepare a surface for microcontact printing and etching by first cutting a small piece from the gold CD (Au-CD) provided.

Dissolve the protective coating on the surface of the Au-CD with nitric acid.

Carefully pour nitric acid into waste container.

Rinse the Au-CD piece with distilled water and dry with nitrogen. This process should leave the relief structure of the Au-CD exposed. This gold piece can now be used as a substrate (along with provided gold-coated silicon wafer pieces) for mCP and etching.

Cut out a stamp from your CD master.

Make a 1 mM solution of octadecanethiol in ethanol and shake it well. This solution is your "ink" solution.

Take a cotton swab and dip it into the above solution. Rub it back and forth across the patterned side of the PDMS stamp for 10 s.

Dry the ink under a stream of nitrogen until dry (approximately 1 min).

Hint (and aside):

To determine the direction of the lines on the PDMS mask shine a laserpointer through the substrate (at 90 deg) held above a piece of whitepaper. Based on the diffration pattern observed, you should be able to determine the direction of lines. This procedure can also be done for CDs after you etch the Au layer off (see etching section below). Note: this video will open in a separate window.

Place the stamp in conformal contact with the gold surface for 5 s or less. Repeat this process with both the Au-CD substrate and the gold-coated silicon wafers provided. For the Au-CD substrate, place the stamp such that the lines of the PDMS stamp run perpendicular to the lines on the Au-CD (determine direction of lines on the mask and the Au-CD using the laser pointer method or previous knowledge). Try stamping the line patterns at different angles. Experiment also with the differently patterned PDMS stamps.

Remove the stamp from the surface. To visualize the pattern, you can breath on your chip. You should see a diffraction pattern if you have transferred the pattern from the stamp to the gold surface. Save one good microcontact printed sample (one that has NOT been etched). Image (1) this sample and (2) those made on Au substrates (not CDs) using LATERAL FORCE MICROSCOPY (LFM).

Dilute the commercial gold etchant with deionized water (1:3).

Stir the etchant well with a stirbar.

Using plastic scissor clips, place your SAM coated gold into the beaker containing the etch solution. Etch for approximately 38-41 seconds. You may have to adjust these times slightly for the best effect. Rinse off the substrate in a stream of water and dry under nitrogen. Look at the patterns on the Au-CD under the optical microscope. Image (1) micron-sized features on the Au substrates and (2) the Au patterns CDs UNDER THE AFM (and if possible, the SEM).

To visualize the Au cross hatch pattern after etching on a CD, you can shine a laser pointer onto the sample and look at the diffraction pattern that is produced. Note: this video will open in a separate window.