Vibro-tactile feedback is, by far the most common haptic interface in wearable or touchable devices. This feedback can be amplified by controlling the wave propagation characteristics in devices, by utilizing phenomena such as structural resonance. However, much of the work in vibro-tactile haptics has focused on amplifying local displacements in a structure by increasing local compliance. In this paper, we show that engineering the resonance mode shape of a structure with embedded localized mass amplifies the displacements without compromising on the stiffness or resonance frequency. The resulting structure, i.e., a tuned mass amplifier, produces higher tactile forces (7.7 times) compared to its counterpart without a mass, while maintaining a low frequency. We optimize the proposed design using a combination of a neural network and sensitivity analysis, and validate the results with experiments on 3-D printed structures. We also study the performance of the device on contact with a soft material, to evaluate the interaction with skin. Potential avenues for future work are also presented, including small form factor wearable haptic devices and remote haptics.

迄今为止，振动触觉反馈是可穿戴或可触摸设备中最常见的触觉界面。通过利用结构共振等现象控制设备中的波传播特性，可以放大这种反馈。然而，振动触觉触觉的大部分工作都集中在通过增加局部顺应性来放大结构中的局部位移。在本文中，我们展示了设计具有嵌入式局部质量的结构的共振模式形状可以在不影响刚度或共振频率的情况下放大位移。由此产生的结构，即调谐质量放大器，与没有质量的对应物相比，产生更高的触觉力（7.7 倍），同时保持低频。我们结合使用神经网络和灵敏度分析来优化提议的设计，并通过 3D 打印结构的实验验证结果。我们还研究了设备与软材料接触时的性能，以评估与皮肤的相互作用。还介绍了未来工作的潜在途径，包括小型可穿戴触觉设备和远程触觉。