Is waking up for Suhoor a requirement for the intention of fasting to be formed, or is the intention formed merely by sleeping with the intention to fast?

Your purchasing and preparing the suhoor includes the intention to fast, and your fast is valid. Your sleeping through suhoor does not invalidate it, for the intention does not require verbalization; rather, it is sufficient to hold it in the heart. The intention follows knowledge, so whoever knows that tomorrow is part of Ramadan and intends to fast it in their heart, their intention is valid.