Abstract: A nanocalorimeter device includes a head that defines first dispensing regions configured to receive first drops of first liquids and a cover that defines second dispensing regions corresponding to the first dispensing regions and configured to receive second drops of second liquids. The first and second dispensing regions form corresponding nanocalorimeter cells when the cover is connected to the head, each nanocalorimeter cell thereby containing first and second drops which are combined during a measurement run into a merged drop. The nanocalorimeter device further includes mini-bars pre-dispensed in the second dispensing regions, respectively, each mini-bar including a high magnetic permeability material. A magnetic driver is configured to generate a rotating magnetic field around the nanocalorimeter cells, where the rotating magnetic field causes the mini-bars to spin, mixing the first and second liquids in the merged drop within each nanocalorimeter cell.