Tissue and vessel treatment devices and respective methods are provided. Devices comprise a flexible treatment layer that comprises a plurality of operable elements configured to be activated to apply the treatment to the obstruction upon bending of the flexible treatment layer beyond a specified curvature threshold and to be de-activated upon a specified decrease of the bending. The treatment layer may comprise optical fiber(s) with the operable elements as emission regions that emit electromagnetic radiation from the core upon bending the optical fiber beyond a specified bending threshold. Devices may be configured as vessel sealing tips for surgical forceps, in which the treatment layer is configured to yield vessel welding and vessel cutting effects.