This paper presents a preliminary investigation of the effectiveness of haptic feedback for design processes involving mechanisms used by a human operator in interacting with an environment. Our example is a case study of the design of an amniocentesis device, which represents a relatively simple and yet meaningful application. We simulated the mechanism, as well as its intended working environment, represented by layered mass-spring surface meshes. The user feels force feedback when manipulating the simulated device via a haptic interface. The user can also interactively update the design by modifying the values of the parameters that describe the mechanism. To investigate the effectiveness of haptic rendering in this design problem, an informal preliminary user study was conducted, where each subject explored a discretized design space of the mechanism. The results of the user study suggest that haptic rendering is effective in expediting the design process for some applications.