Needle bending is a significant cause of error in biopsies, leading to lesion missampling and consequent cancer misdiagnosis. This paper presents the experimental testing of a new mechanism that detects the needle bending as soon as it occurs and immediately reduces the insertion force. This is achieved without employing sensors or actuators. Our in-vitro experiments on silicone-rubber phantoms indicate that the device can avoid deep insertions with deflected needles, thus potentially reducing the associated risks.