The human hand exhibits a high number of degrees of freedom, enabling precise execution of dynamic tasks and seamless interaction with the environment. In contrast, rigid robotic hands struggle to replicate this dexterity, limiting their ability to perform natural movements. To address this gap, this work presents the development of a flexible robotic hand bio-inspired by the biomechanics of the human hand. The proposed design integrates Shape Memory Alloy (SMA) actuators and silver-coated polyamide sensors to achieve a lightweight, compact, and functional structure. The final prototype consists of six actuators, allowing independent flexion of each finger and thumb opposition, with each actuator generating a force of up to 58 N. The robotic hand is 3D printed using a combination of flexible and rigid recyclable materials, ensuring structural rigidity in the palm while providing flexibility in the fingers, all while maintaining dimensions comparable to a human hand. The total weight of the robotic hand, including the actuators, is less than 300 g.