"trigger an idea" is correct and usable in written English.
You can use it when you want to prompt another person's thoughts or opinions about a certain topic. For example, "Let's think of strategies to solve this problem. Has anyone been triggered by an idea yet?".
The first time you do it, something happens to trigger an idea, from which everything falls into place.
You might only pick up a book because you can't bear to tell your colleague you spent another night Instagramming your cat – but that book might stretch a muscle or trigger an idea that makes you try something new.
I like creating books for people who can't read, and I like to inspire, so, hopefully, this book will trigger an idea or two.
I never know what's going to trigger an idea, so I like knowing as much as I can and having a wide variety of experiences.
You have starting points with any pictures or text you have left - they might trigger an idea for a picture or journal entry.
Anytime an idea was suggested to us or something triggered an idea in us, we jotted it down, and then did regular debriefs as a team to share these ideas.
If the lemon tart made Harris want to become a chef, the overall experience at Nico at Ninety triggered an idea that he would eventually realise at the Sportsman.
A vivid dream in college changed his course and triggered an idea: a chair in a bottle, an object that once had a use but no longer does, except to look beautiful.
Roger Lowenstein triggers a provocative idea.
It would be good to think that Sir Reg's departure will trigger a battle of ideas as well as a contest of individuals.
Anthony Gregory is a small-voiced Nanki-Poo but looks the part, while Graeme Danby is a fine Pooh-Bah, whose multi-tasking as chancellor of the exchequer and lord chief justice may have triggered a few ideas for the head of the civil service Sir Jeremy Heywood, who was sitting in the stalls on the first night.
