The present invention facilitates in silico evaluation of molecules for biological activity by providing a computer-based method to predict whether oligonucleotides may possess biological activity and the efficacy of the biological activity based on the three-dimensional structure and charge characteristics of the oligonucleotides. In a preferred embodiment, a test structure includes a feed line, a stress line disposed proximate the feed line, and a conductive feature disposed between the stress line and the feed line. The adjustability of the needle electrodes allows the depth that the needle electrodes penetrate through tissue to be adjusted. within the temperature range from 30\xb0 C. The back plate is located at a position that is flush with or slightly below the surface in which the footing is buried.