Robotics has advanced tremendously from performing simple pick-and-place tasks in structured environments to operating in a range of real-world environments and terrains full of uncertainties. Often these advances have been motivated by biological systems. [1] As a result, the field has grown from simple robotic arms performing preprogrammed industrial tasks [2] to human/ animal-like robots or prosthetic devices that autonomously conduct wide-ranging tasks using various sensory modalities. [3][4][5] The advances in robotics have closely followed the developments in the fields of functional materials, sensing, actuation, and communication technologies, as well as artificial intelligence, which altogether have enabled robots to mimic the morphology and functionalities of biological systems to a high degree. [6] As an example, the implementation of large-area tactile skin or electronic skin (e-skin) has allowed robots to exploit tactile feedback from the whole body for working in unstructured or cluttered environments, just as animals do. [5,7] Likewise, miniaturized and yet powerful actuators and electronic components have allowed the development of dexterous hands and agile robots. [8] In recent years, 3D/4D printing has also opened the ways for the development of sensitized robots with complex shapes and soft structures. [9,10] Thus, advances in robotics have closely followed the technological advances in other areas such as electronic hardware, advanced materials, and manufacturing. However, there is one critical area where robotics appears to have largely missed to follow the technological trend, i.e., the energy needed to power the robots.A reliable source of energy is critical for the smooth operation of autonomous robots, particularly in environments where mains power is not readily available. In fact, the majority of applications today require robots to be autonomous, and as such, they must rely wholly on batteries for their source of power. Analyzing the state of the art, we note that not much progress has been made in terms of adopting the advanced energy solutions in the robot, despite major advances in battery technology. [11] Starting from the first autonomous wheel-based robot Shakey [12] in 1966 to the state-of-the-art humanoid robots developed during the last 30 years and the quadrupedal MIT cheetah robot [13] of 2018, the battery the autonomous robots use has improved only in terms of light weight and energy density (Figure 1). [14][15][16] In contrast, the energy-storage technology itself has evolved from the bulky and leaky liquid electrolyte-based systems [17,18] to printed batteries, flexible supercapacitors (SCs) with safe electrolytes, and elegant textile-based devices. [19][20][21][22] The battery technology has improved in terms of a Watt-to-weight ratio, form factors, lifetime, ruggedness (thermal and chemical), etc., and nowadays, flexible, stretchable, and printed batteries are increasingly being explored.The energy requirement of robots can also be met with the harvesting of renewa...