For some reason, taking a year off to travel, volunteer, or experience the world isn't looked at in the same negative career light that wanting to only work part-time is, particularly if you have demonstrable successes at your last employer. It shows passion, engagement, and the ability to take responsibility for your own life, and many employers assume that will transfer over to your job performance at your next job. You're at a slight disadvantage in salary negotiations because they don't have to lure you away from your existing job, but you can make up for this by applying to many jobs (ideally through connections) at once.
I've heard it's also better on the "life" side of things as well, as you can throw your whole being into whatever you experience in your free time, and not just settle for the scraps you can fit around your job.
I took about a year off to explore alternative careers and personal pursuits after working at a tech firm for 3 years. I returned to the industry and was recruited within a few months back into a spinoff from my original firm.
Of course, this presupposes that you maintain your skills, and that you don't burn any bridges when you leave.