Without whom, I am nothing The overall kinesthetic immersive experience in a haptic interactive virtual environment is the synthesis of the human user, the haptic user interface (HUI), and virtual environment (VE) – all of which playing critical roles. Our focus will be on the development of advanced HUIs for providing the users with sophisticated tactile or force feedback during interaction with virtual environments with innovative features including active and passive manipulation assists. Desirable features for high-performance HUIs include: human matched force capabilities, sizeable workspace, low inertia, high stiffness, low friction, back-drivability, near-zero backlash, and gravitational counterbalancing. Parallel-architecture haptic devices offer significant advantages over serialarchitecture counterparts in applications requiring high stiffness and high accuracy. To this end, many haptic devices have been created and deployed by modularly piecing together multiple serial-chain arms to form an in-parallel system. Furthermore, recent haptic device designs such as the Sensable‟s Phantom Premium line of haptic devices and

Exoskeletons are a new class of articulated mechanical systems whose performance is realized while in intimate contact with the human user. The overall performance depends on many factors including selection of architecture, device, parameters and the nature of the coupling to the human, offering numerous challenges to designevaluation and refinement. In this paper, we discuss merger of techniques from the musculoskeletal analysis and simulation-based design to study and analyze the performance of such exoskeletons. A representative example of a simplified exoskeleton interacting with and assisting the human arm is used to illustrate principal ideas. Overall, four different case-scenarios are developed and examined with quantitative performance measures to evaluate the effectiveness of the design and allow for design refinement. The results show that augmentation by way of the exoskeleton can lead to a significant reduction in muscle loading.