Improved microneedle arrays are provided having a sufficiently large separation distance between each of the individual microneedles to ensure penetration of the skin while having a sufficiently small separation distance to provide high transdermal transport rates. The compressor also includes a plurality of pistons each of which are slidably positioned within a corresponding cylinder bore, and a drive mechanism adapted to reciprocate each of the pistons within their corresponding cylinder bore. Further, an object of the invention is to provide a method for manufacturing paper andor board, which method makes use of chemical pulp having said filler incorporated therein as dried in chemical pulp bales.