This article reports the development and evaluation of a self-powered intracardiac pacemaker (SICP) in swine models. The SICP is designed to harvest biomechanical energy from cardiac motion, eliminating the need for batteries and reducing the risk of complications associated with traditional pacemakers. The device, weighing 1.75 g and with a volume of 1.52 cc, is capsule-shaped and can be delivered through a catheter into the right ventricle via the intravenous route. It integrates an energy harvesting unit (EHU), a power management unit & pacemaker module (PMU&PM), and hooks for secure placement. The EHU, based on triboelectric nanogenerator technology, converts mechanical energy into electrical energy, generating an open-circuit voltage of 6.0 V and a short-circuit current of 0.2 μA. In vivo testing in swine showed that the SICP maintained stable pacing function over a three-week period, with no significant changes in ECG or blood pressure. The device also demonstrated good biocompatibility, with no observed inflammation or rejection at the implantation site. This study provides a promising approach for long-term, leadless, and battery-free pacing, offering a potential solution for improving the lifespan and reliability of implantable bioelectronic devices.This article reports the development and evaluation of a self-powered intracardiac pacemaker (SICP) in swine models. The SICP is designed to harvest biomechanical energy from cardiac motion, eliminating the need for batteries and reducing the risk of complications associated with traditional pacemakers. The device, weighing 1.75 g and with a volume of 1.52 cc, is capsule-shaped and can be delivered through a catheter into the right ventricle via the intravenous route. It integrates an energy harvesting unit (EHU), a power management unit & pacemaker module (PMU&PM), and hooks for secure placement. The EHU, based on triboelectric nanogenerator technology, converts mechanical energy into electrical energy, generating an open-circuit voltage of 6.0 V and a short-circuit current of 0.2 μA. In vivo testing in swine showed that the SICP maintained stable pacing function over a three-week period, with no significant changes in ECG or blood pressure. The device also demonstrated good biocompatibility, with no observed inflammation or rejection at the implantation site. This study provides a promising approach for long-term, leadless, and battery-free pacing, offering a potential solution for improving the lifespan and reliability of implantable bioelectronic devices.