The lens cavity (74) has a lens gap (h) between 10 microns to 120 microns, and preferably 40 microns to 60 microns.

The solvents have IR spectra, which have no peaks between about 8.25 micrometers and about 8.75 micrometers and between about 9.50 micrometers and about 10.00 micrometers.

a scratch proof coating of a thickness of 45 micrometre (± 5 micrometre

Micrometers and callipers (including vernier, dial indicating or electronic callipers

Micrometers and callipers (including vernier, dial indicating or electronic callipers

Micrometers and callipers (including vernier, dial indicating or electronic callipers

The average grain size preferably ranges between 1.4 micrometers and 2.5 micrometers.

The microneedles are of a height of approximately 400 micrometers to approximately 750 micrometers.

The fibreglass has a nominal diameter in a range of 3 micrometers to 15 micrometers.

Said multimode fibre has a core with diameter greater than 30 micrometers, even greater than 50 micrometers.

The microcantilevered spring element (3) is approximately 1 to 100 micro-meters long, approximately 1 to 50 micro-meters wide, and approximately 0.3 to 3.0 micro-meters thick.

The compression path amounts to 10 micrometers at an extension R of the structures of 50 micrometers.

The desired plate thickness removed is no more than about 10 micrometers, and preferably about 5 micrometers.

The parameters measure on the order of micrometers.

The optical element (30) has a thickness of less than a few hundreds of micrometers especially less than 100 micrometers.