There are lots of other word pairs with an -s- and -c- (practise/practice, advise/advice) that are differentiated by the fact that one is a verb (the -s- one) and one a noun (the -c- one). These two have become slightly more separated and slightly less confused, I feel (but maybe you’ve found differently).
To devise is a verb meaning to plan or invent something (usually something such as a process, procedure or mechanism that is quite complicated). “He devised a route to get from Manchester to Birmingham, not using any motorways”, “The clockmaker devised a mechanism for making a watch show the time in 15 different time zones”.
A device is a noun meaning a piece of mechanical or electronic equipment made for a particular purpose (“He constructed a device for making American recipes using English measuring instruments”), or a plan, trick or scheme (and, by extension, a form of words that’s intended to produce a particular effect: “She used a metaphorical device to explain quantum mechanics in her astounding poem”).
So, you could, indeed, devise a device, but I don’t think you’d want to, simply because of the cumbersome repetition (just like you don’t practise practices!).