An apparatus includes a support structure defining therein substantially parallel cavities extending from a first side of the support structure to a second side of the support structure. The apparatus also includes optical fiber cores each extending from the second side through a corresponding cavity and protruding axially at the first side. The axial protrusion tapers from a first diameter down to a second diameter. The apparatus additionally includes a light emitter optically connected to the optical fiber cores and configured to emit light thereinto. A cut-off size associated with the light is greater than or equal to the second diameter such that an evanescent electromagnetic wave is generated at the cut-off portion. The apparatus further includes light detectors each being optically connected at the second side to a corresponding optical fiber core and configured to measure an intensity of the light reflected from the cut-off portion.

The disclosure relates to methods of printing indicia on a substrate using a tip array comprised of elastomeric, compressible polymers. The tip array can be prepared using conventional photolithographic methods and can be tailored to have any desired number and/or arrangement of tips. Numerous copies (e.g., greater than 15,000, or greater than 11 million) of a pattern can be made in a parallel fashion in as little as 40 minutes.

The disclosure relates to methods of printing indicia on a substrate using a tip array comprised of elastomeric, compressible polymers. The tip array can be prepared using conventional photolithographic methods and can be tailored to have any desired number and/or arrangement of tips. Numerous copies (e.g., greater than 15,000, or greater than 11 million) of a pattern can be made in a parallel fashion in as little as 40 minutes.

The disclosure relates to methods of printing indicia on a substrate using a tip array comprised of elastomeric, compressible polymers. The tip array can be prepared using conventional photolithographic methods and can be tailored to have any desired number and/or arrangement of tips. Numerous copies (e.g., greater than 15,000, or greater than 11 million) of a pattern can be made in a parallel fashion in as little as 40 minutes.