The surface coating of tungsten needles can have a significant effect on their biocompatibility. In general, tungsten is not considered a biocompatible material and may cause negative reactions when in contact with living tissue. However, coatings such as gold, platinum, or iridium can improve the biocompatibility of tungsten needles, making them suitable for certain biomedical applications. These coatings can also enhance the conductivity and durability of the needles, making them more effective for use as microelectrodes in medical research or treatment.
