Bio-inspired design of a self-propelling and steerable needle

The design of a self-propelling, steerable needle was inspired by a wasp’s ovipositor, a thin, flexible needle-like structure used for laying eggs into larvae hidden inside fruit or wood. The needle’s potential medical applications include localised therapeutic drug delivery and tissue sample removal (biopsy). The instrument design, as described in this Mikroniek article, features three or more wires that are moved back and forth inside tissue sequentially. Through friction, a net pulling motion of the tissue towards the actuation unit is generated, resulting in the instrument moving forward inside the tissue. Different sequences of wire actuation can achieve either straight or curved trajectories.