Atomic clocks today have become widespread tools in several fields of our daily life. For example, they are used to maintain the official timescales, to synchronize telecommunication networks, and they are at the heart of satellite navigation systems. In an atomic clock, the frequency of a quartz oscillator is stabilized to an atomic microwave transition that serves as a stable reference. In this way, sudden jumps or slow drifts of the quartz frequency are corrected and its stability is improved. Then, by counting a certain number of the quartz frequency cycles, the precise duration of a second can be established. In this project we address miniaturized atomic clocks that may finally have a volume of one cubic centimetre only, can be powered over extended time from standard batteries, and still show frequency stabilities several orders of magnitude better compared to a standard quartz. Such miniature atomic clocks may find applications in a wide variety of applications on ground and in space: satellite navigation and positioning, secure telecommunications, enhanced functionalities in mobile equipment, and others. On a longer time scale, the developed building blocks may constitute the basic components of other quantum sensors (atomic magnetometers, atomic gyroscopes, etc.) or future quantum communication systems. The main objective of the research is not primarily an integrated functioning atomic clock, but focuses on more prospective scientific studies on selected relevant topics and challenges that may lead to separate more product-oriented developments. The five involved research teams will - both independently and jointly - pursue the following investigations towards novel clock components and schemes, aiming at completely new solutions: New cell manufacture and filling techniques; new schemes for coupling the microwave to the atoms; new solutions for the light source and optical excitation of the atoms; evaluation of the interoperation of the new components in a clock; new strategies for overall clock integration (packaging) of the components and lifetime-limiting effects. The teams involved in this project have taken first steps to develop building blocks for a miniature atomic clock since 2005. This collaborative work is mainly focused on the development and testing of micro-fabricated rubidium vapour cells and overall physics package and is carried out in the frame of national as well as international research programs: CIMENT (2006-2008 financed by CUS), mUSO (2007-2009 financed by the European Space Agency), and MAC-TFC (2008-2011 financed by EU through the 7th framework program) in view of a future valorisation of the results.