All kitchen knives, whether professional quality or inexpensive, need a blade tune-up now and then. Since knife is dangerous, as a utensils to sharpen it, knife sharpener must be safe, user-friendly and Versatile. In this post, we rounded up 11 Innovative and Functional Knife Sharpeners, which not only professional chefs but also householders can easily work with it and get work done quickly and safely.