Development of neural interfaces and energy harvesters towards self-powered implantable systems for healthcare monitoring and rehabilitation purposes

Despite its great promise, neural interface has yet to substantially impact modern healthcare monitoring and therapeutic interventions. However, considering the recent development of self-power solutions, data transmission technologies, and artificial intelligence, neural interface has the potential to transform future clinical applications. Together with the recent self-powered energy harvesting technologies, neural interfaces are evolving towards fully implantable systems. Here, we first review the progress and current status of neural interfaces, start from the well-established neuromodulation protocols and efforts to translational applications, then move on to milestones of neural interface development, and end with the review on considerations and requirements of active and inactive materials. With the knowledge of neural interface current status, we further review implantable systems which are built on top of the neural interfaces. Particularly, we review well-established powering solutions. Furthermore, we summarize the recent demonstrations of direct tissue stimulation with self-powered energy harvesters in chronological order. In the end, we discuss the future opportunities and challenges in the direction towards self-powered systems for healthcare monitoring and rehabilitation purposes.