Possible, yes. Good idea, no. Hmm, now I need my links to a dozen threads arguing this point.
By flashdrive, do you mean an SSD or a USB thumb drive? If the latter, don't do it, period. They aren't fast enough or good enough; you will get a slow setup that loses your data.
If you mean SSDs, you are much, much better off buying a larger SSD in the same product line than two smaller ones and putting them in RAID0.
RAID 0 multiplies the chances of failure. RAID0 helps more with HDDs, where seek time is dominant, by allowing data to transfer from one drive while the other is seeking. SSDs have negligibile seek time. There are a few people here who will do this, most will avoid it like the plague. My advice: Unless you have a very specific need that RAID 0, and only RAID 0, will fulfill, don't do it.