BEP : "Design of a guiding mechanism for the plasma needle"

In 2001 research from the Elementary Processes and Discharges in Gas Discharges group (EPG) at the Eindhoven University of Technology has led to the development of the plasma needle. This new type of plasma can be sustained at atmospheric pressure and operates at ambient temperature, making treatment of biological tissue possible. Research on the plasma needle is still in its early phase, the theory of plasma is mostly known, but virtually no practical data is available. The plasma needle was operated by hand and therefore test that were done are not representative and reproducible. Research has shown that the plasma itself can serve as a positioning sensor. The existing setup to control the position of the plasma needle has proven to give an insufficient result. Controllers tested on this setup were unstable and unable to control the position to the required accuracy. After reviewing this apparatus various suggestions will be done for improvements. A guiding system using aerostatic bearings is suggested as well as a system using leaf springs. Comparison of the two bearings show that in this stage of the research and with the proposed treatment area the latter option is the best suitable. This leaf spring arrangement is then worked out in more detail, giving an impression of the required actuator forces and various dimensions. Furthermore details are given on a voice coil actuator, the chosen actuator for the leaf spring design. After that a new design will be given for the plasma needle.