One of the main diagnostic limitations of current gastrointestinal (GI) capsule endoscopes is that they cannot get biopsies, thus requiring follow-up with flexible endoscopy whenever a suspicious lesion is identified. The ability of getting biopsies from a wireless capsule would save time and costs associated with the procedure, reducing at the same time invasiveness and discomfort for the patient. The Crosby capsule, designed in 1957, exploits a small tether to suck tissue, to activate spring-loaded knife and to manage device retrieval. However, invasiveness of the procedure is still relevant and requires sedation [1]. Two compact mechanisms have been recently proposed for wireless biopsy. The first takes advantage of a spring actuated rotational razor [2], while the second exploits Shape Memory Alloy (SMA) to actuate a micro-biopsy spike [3]. Due to the harsh environment of the GI tract and the absence of stabilization during sampling, both these devices have a limited efficacy. In order to improve efficacy while reducing capsule size, we propose a completely magneto-mechanical mechanism which does not require onboard batteries and actuators.