Abstract Solid state based quantum dots (QD) are heavily discussed for applications as qubits, but also provide a beautiful playground for basic research on artificial molecules. First, concepts needed to understand transport and charge spectroscopy measurements on coupled QDs will be developed. Then experimental results on a few electron triple QD, a double QD quantum ratchet and interaction mechanisms involved are discussed. Our few electron serial triple QD is electrostatically defined in a standard GaAs/AlGaAs heterostructure containing a two-dimensional electron system. Ground state stability diagrams detected with a single quantum point contact (QPC) demonstrate complete control of the triple QDs charge configuration in the few electron regime. The complex interplay between charge states of the three coupled QDs near points of high degeneracy will be discussed. In this regime we observe electron transport through the three QDs reflecting quantum cellular automata physics. The remainder of the talk will be devoted to the interaction of a strongly driven QPC with another unbiased QPC or a double QD. These experiments can be seen in the context of back-action of a charge detector (the QPC) onto a qubit (the double QD). Using the strongly driven QPC as non-equilibrium energy source we realize a double QD quantum ratchet. A second experiment involving two QPCs illuminates the possible role of electron-phonon interaction in such devices.