Günter Mayer

Nanotiterplates for combinatorial chemistry.

Miniaturization has grown to be a driving force in modern chemical and biochemical laboratories. Combinatorial explosion demands for new pathways for the synthesis and screening of new substances which can act as leads in drug discovery. Highly parallelized automata that can handle the smallest amounts of substances are needed. However, the development is not always straightforward since new problems also arise in miniaturization, e.g. increasing importance of surface properties of utilized devices and evaporation of liquids. This paper reports on recent developments on the field of miniaturized reaction vessels called nanotiterplates. A survey on fabrication technologies as well as applications of nanotiterplates is given. Special emphasis is given to results of the development of an automaton for miniaturized synthesis and screening. Besides the mere fabrication of nanotiterplates with integrated microsieve bottom membranes, examples of applications in chemical synthesis and bio-assays are given. Further topics are the characterization and specific adaption of surface properties and investigations on the evaporation of solvents and measures for prevention.

Nano Titer Plates: Micro Compartment Arrays for Biotechnological Applications

Arrays of micro compartments for combinatorial chemistry and biotechnological applications have been fabricated by means of photolithography and anisotropic chemical wet etching. Integration levels of 16′000 per 4″ wafer have been achieved. Optically transparent membranes or micro sieves allowing for rinsing between process steps can be incorporated. For the investigation of thermally activated biochemical reactions a micro compartment array with integrated thermo control has been developed, which allows the adjustment of thermal gradients over a 4″ wafer. Peak temperatures exceeding 90 °C at the center of the wafer as well as temperature gradients with ΔT = 40 °C could be demonstrated. To avoid fluidic crosstalking between adjacent compartments a technique has been developed, that allows selectively hydrophobizing the rims of the compartments.