Fig.1. a). Profile of a single crater in the direction of the red line at the lower picture. From this profile, the structural parameters of a microvessel such as diameter w, depth d and radius of curvature R are obtained. The dashed black line corresponds to the fit of the lens profile to a circle with radius R. (b) Average depth d and diameter w of the craters of five arrays as a function of deposited drops of toluene on the polystyrene surface. Error bars are the standard deviation of the data.

Fig. 2. (a). Arrays of microlenses imaged by a confocal profilometer. The upper picture shows concave microlenses obtained by ink-jet printing. The number of deposited drops is increased in the y-direction. Below, convex microlenses obtained by template casting from the concave ones. (b). The graphs present the profile of the arrays along the full and dashed green lines shown in the upper image.

Fig. 3. Scheme of the Laser Scanning Confocal Microscopy setup. Abbreviations: BS = beamsplitter, DBS = dichroic beamsplitter, GS = galvanometric scanner, BE = beamexpander, PMT = photo-multiplier, PH = pinhole, EM = emission filter, TL = tube lens, SL = scan lens, CL = collimator lens.

Fig. 4. (a). Focal lengths f of an array of microlenses as a function of the number of deposited drops. Red triangles are the calculated values and the empty diamonds correspond to the experimental data. (b) Confocal reflection/transmission scan image in the X-Z plane of a convex microlens array. The vertical green lines are the transmitted laser beams. The reflection scan image has been merged with the transmission one, and can be distinguished at the bottom of the picture as a bright green horizontal line. (c) Intensity profile along the Z-axis of a transmitted laser beam through a microlens obtained with 4 deposited droplets. This beam is pointed at (b) by the white arrow at its experimental focal point. The black line is the experimental intensity and the red one is the fit to a Gaussian peak. The position of the maximum of this fit determines the experimental focal length of the microlens.