IF you have the data ports on a RAID-capable controller and the power supply connectors available (always easy to add more via adapters) you can go two ways. Either simply install and use them a separate drives or use the JBOD version of RAID to combine several into one volume treated as a single drive. I'd be inclined not to use the smallest ones.
Have you considered mounting a few in one or more external drive enclosures and using them as backup devices that can be disconnected and stored offsite?