Using Arduino to get low intensity AC current pulses

Hello, I want to make a device which will have a AC electric current in microamperes every 3 seconds, with frequency of at least 1000 Hz. My job will be to experiment about which frequency will exactly do the job, as well as exact intensity of electric current. That device could be made without Arduino and basically all I know is that I will need a timer. I want to realize this device with Arduino because I plan also to put some sensor later on, but first I need to get that output. Since I am not an expert in designing circuits, I would very much appreciate any help.