Am I expected to borrow student loans?

No.

Dartmouth's strong commitment to an affordable undergraduate education ensures that students will graduate without the burden of expected student debt. If you qualify for need-based financial aid, your package will not include a student loan, regardless of income level, or citizenship. 

Student loans are still available if needed. Some student or parents may choose to use a student loan to replace some or all of their EFC or work expectation, or to assist in covering the health plan or computer costs.