What glue to use to make a resin sticker that adheres well to the back of an iPhone?

Question

I am in the process of creating a few domed stickers for my phone, like the ones shown here. I have created these in a silicone mold and want to apply some kind of glue to the backside so that I can adhere this to the back of my iPhone. I tried a few different adhesives:

1. Glue stick: The glue isn't very strong and the sticker comes off easily
2. Repositionable spray adhesive: This one didn't work that well either. It adhered alright in the first try but then after removing the sticker once, the adhesion was lost.

Can you recommend an adhesive that will work for me? I want the adhesion to be strong enough so that it sticks to the phone, however, with a strong pry, the sticker should be able to come off. The phone can be bare, so the backside is metal alloy or it might have a plastic case.

Answer 1

If you can be certain that the surface is clean and more important, flat, consider to use a variety of gecko tape, also known as nano tape.

image from linked site

I've purchased a sheet of the material and discovered that it works extremely well on smooth surfaces, including plastic. I have a USB hub with a piece attached, which bonds well to the device, but was problematic when the opposing surface had texture. This was solved with a piece of ordinary packing tape trimmed to be less obtrusive, attached to the textured surface.

One of the uses I've performed was to secure an electric toothbrush timer display to a mirror. This placed the display in a position of vertical stress, aka gravity, yet it bonded and held for a number of years, but was easily removed and replaced for battery changes.

Various sources of the material result from a search, making it impractical to list any specific one.