A device includes a plurality of skin penetrating devices for delivering or withdrawing a substance through the skin of a patient. The device has a support formed with a top and bottom end and a plurality of channels extending axially through the support. A plurality of the skin penetrating members is positioned in the channels with a tip extending from the bottom end of the support. A coupling member is attached to the support for coupling with a fluid supply and directing the fluid to the skin penetrating members. The skin penetrating members have a length of about 100 microns to about 2000 microns and are about 30 to 50 gauge.