In lieu of that make rewards for reading. Pick a book in a category that they like and for a reward perhaps offer a comic book or sticker book as a prize for finishing a book. I own and operate 4 used bookstores and talk to alot of parents who use this type of idea. Bringing your children to the bookstores and browsing around with them is a fun activity, make a fun lunch stop afterward part of the goal for them.

I am also an author of science fiction, The Charon Covenant and was fortunate that my son also loves science fiction. When he was younger we picked a book and had family night to read and discuss the book together. Pick a night each week as family night, it was alot of fun and he still remembers those nights.