A device and a method for locking and/or unlocking a motor vehicle opening panel and vehicle having the device. The device includes a detection wall having an inner side and an opposite outer side, the outer side forming a contact detection region, and a detection component arranged against the inner side for detecting contact between a user's finger or hand and the outer side. The detection component includes a sensor having a layer of a piezoelectric material which has surface undulations in the form of ridges. The layer of piezoelectric material is configured to detect predetermined contact on the outer side with a view to controlling the locking or unlocking of the opening panel.