Up to 15 subjects will participate in three 7-day study arms using insulin lispro, aspart, and glulisine in the bionic pancreas in random order. The co-primary outcomes will be mean CGMG and fraction of time spent with CGMG <54 mg/dl with comparisons made between arms for individual participants. In order allow statistical comparisons between insulin analogs within a single participant, the mean CGMG and % time <54 mg/dl will be calculated for each day of each arm, and means of daily means (n=7 for each arm) will be compared for each three pairwise comparisons between arms. Secondary analyses will include time in glycemic ranges (<50, <60, <70, 70-120, 70-180, >180, >250 mg/dl), coefficient of variation, mean postprandial excursion (difference in CGMG from the time of meal announcement to the peak CGMG in the first 4 hours after the meal announcement), number of symptomatic hypoglycemic events, grams of carbohydrate consumed to treat hypoglycemia, and TDD of insulin. For each outcome the mean of daily means will be compared for each three pairwise comparisons between arms.