JumpMod: Haptic Backpack that Modifies Users' Perceived Jump

Vertical force-feedback is extremely rare in mainstream interactive experiences. This happens because existing haptic devices capable of sufficiently strong forces that would modify a user's jump require grounding (e.g., motion platforms or pulleys) or cumbersome actuators (e.g., large propellers attached or held by the user). To enable interactive experiences to feature jump-based haptics without sacrificing wearability, we propose JumpMod, an untethered backpack that modifies one's sense of jumping. JumpMod achieves this by moving a weight up/down along the user's back, which modifies perceived jump momentum—creating accelerated & decelerated jump sensations. In our second study, we empirically found that our device can render five effects: jump higher, land harder/softer, pulled higher/lower. Based on these, we designed four jumping experiences for VR & sports. Finally, in our third study, we found that participants preferred wearing our device in an interactive context, such as one of our jump-based VR applications.