A method and device are described for applying a microprotrusion member (44) including a plurality of microprotrusions (90) to the stratum corneum with impact. The method and device are used to improve transport of an agent across the skin for agent delivery or sampling. The applicator (10, 60, 80) causes the microprotrusion member (44) to impact the stratum corneum with a certain amount of impact determined to effectively pierce the skin with the microprotrusions (90). The preferred applicator (10, 60, 80) impacts the stratum corneum with the microprotrusion member (44) with an impact of at least 0.05 joules per cm.sup.2 of the microprotrusion member (44) in 10 msec or less.