Pittsburgh is better than the others in terms of not having high college GPA hurdles to get into the bioengineering major after enrolling at the school:
Pittsburgh: 2.0
VT: 3.0
Purdue: 3.2
Wisconsin: 3.5 technical, 3.0 overall (even if direct admit, need these GPAs to stay in the major)
Verify that UConn is direct admission to the bioengineering major for you. If not, then it will be competitive to get into the bioengineering major as described at https://undergrad.engr.uconn.edu/prospective-students/admission-guidelines .
You probably want to earn a college GPA of at least 3.0 to avoid getting screened out of interviews for internships and jobs due to GPA, but you do not want possible first year stumbles to force you out of your major early.