Current developments in the field of microfluidic technology allow accurate handling of liquid volumes in the nanoliter to microliter range, in miniaturized systems in which sensing elements to monitor chemical processes on-line can be integrated. This development is especially relevant for the field of chemical analysis in the life sciences where only limited sample volumes are available. This contribution will give a number of examples of integrated microfluidic devices which use sample volumes of 1 microliter or less, including devices which emply NMR, IR, or MS. A second class of topics that will be discussed is that of microreaction systems in which physical principles are used to stimulate chemical activity. In the discussion of the latter topic the focus will be on the use of ultrasound.