Haptic technology, or haptics, is a tactile feedback technology which recreates the sense of touch by applying forces, vibrations, or motions to the user. So an object can have resistance to motion, or even push back as force is applied. The idea is to make an object, often a controller of some kind, feel like it would in the mechanical real world. This is a pretty interesting and potentially very deep area of exploration.
Stanford University created an online course in haptics that uses a basic device called the Hapkit cheap generic viagra. They provide complete instructions and parts list for making your own, though it does require the use of a 3D printer and/or laser cutter to make some of the parts. Also, some essential parts, such as the core motor, make not be easy to obtain at a reasonable price. However, for the electronic VR hobbyist, this could be a worthwhile exploration into an important part of immersive technology.
The online intro course in Haptics is being offered beginning October 1. See the website for full details.