基于炭黑填充导电橡胶的压力/温度传感器非线性特性

通过研究电阻率和电阻几何系数对"负电阻-压力系数"(NPCR)和"正电阻-温度系数"(PTCR)的影响,分析了炭黑填充导电橡胶(导电炭黑/橡胶)的压力/温度传感器的非线性特性。结果表明: 导电炭黑/橡胶的NPCR和PTCR效应产生非线性的主要原因为电阻率的非线性变化; 当炭黑体积分数接近渗流体积分数时,其电阻率对体积的变化敏感程度高,此时,导电炭黑/橡胶的NPCR和PTCR效应的非线性特性较强; 由于导电炭黑/橡胶的体压缩系数大于其热膨胀系数,且导电炭黑/橡胶在压力场和温度场下的形变过程不同,导电炭黑/橡胶NPCR效应的非线性强于PTCR效应的非线性。     

柔性触觉传感器用温度敏感导电橡胶的电阻-温度模型

以通用有效介质理论为基础,得出柔性触觉传感器用温度敏感导电橡胶的电阻-温度计算模型。采用炭黑-硅橡胶导电复合体系(导电/炭黑橡胶)作为实验材料,对该模型进行了实验验证。结果表明,在填料分布均匀、体积分数接近渗流体积分数等边界条件下,电阻-温度计算模型与实验结果吻合,表现出一致的"电阻-正温度系数"(PTCR)变化规律。在温度场的作用下,基体的体积膨胀而导致炭黑浓度被稀释的过程对PTCR效应存在重要影响;基体的体积膨胀导致材料形状的改变对PTCR效应无显著影响。     

机器人触觉传感技术研发的历史现状与趋势

触觉是机器人实现与外部环境直接作用的必需媒介．相对其它机器人传感技术触觉传 感技术已明显落后．本文从总体上简要回顾触觉传感技术研发历程，分析指出其中的不足与 主要原因．在简述目前触觉传感技术研发的现状后，介绍分析机器人技术发展的新趋势及随 之而来的触觉传感技术发展趋势．对今后触觉传感技术的研发提出我们的见解．     

用于机器人皮肤的柔性多功能触觉传感器设计与实验

为实现智能机器人皮肤对三维力和温度的检测,设计并制作了一种柔性多功能触觉传感器.基于碳黑-硅橡胶显著的压阻效应设计了四电极对称结构的三维力传感器,基于碳纤维-PDMS(聚二甲硅氧烷)显著的温度敏感效应设计了叉指电极结构的温度传感器,分析了检测三维力和温度的工作原理.针对两种导电复合材料存在的力学/温度敏感特性交叉干扰问...     

RBF神经网络在柔性触觉传感器解耦中的应用

针对柔性触觉传感器模型高度非线性、解耦难度大等问题,提出一种有效的方法来模拟柔性触觉传感器在实际应用中含噪声的情形。首先在理想条件下的传感器模型上添加不同幅度的高斯白噪声并建立其数学模型,之后通过K-均值和递归最小二乘法优化RBF神经网络,并利用优化后的RBF神经网络算法逼近受噪声干扰的传感器阻值与形变之间的高维非线性映射关系,最后基于不同的展开幅度通过行列阻值解耦出传感器三维形变信息,获得了较好的解耦精度。解耦结果表明,RBF神经网络算法具有较强的鲁棒性和抗噪声能力,能够很好地逼近含噪声的传感器高维非线性数据之间的映射关系。     

基于MSP430的肌电假手系统设计

在对人体表面肌电信号研究的基础上,设计出一种肌电假手系统,其中包括肌电信号采集调理系统和假手控制系统。肌电信号经信号调理电路放大、滤波、陷波后,由低功耗的MSP430F149单片机进行A/D转换、特征计算。单片机结合肌电信号与触滑觉传感器反馈的信息来控制电机转向与转速,从而控制假手做出相应动作。通过实际采集的肌电信号在示波器上显示的波形与假手的动作进行对比,说明系统设计是合理有效的。     

遥控机器人触觉显示器

操作遥控机器人时，希望将远方的触觉传感器的信息以触觉方式重现给操作者．这就需要触觉显示部件．本文介绍了触觉显示部件的原理，发展和分类，描述了人类的触觉生理机制，并对触觉显示部件在遥控机器人中的应用及发展前景作出评价     

基于MEMS微触觉测头和纳米测量机的特征尺寸测量

针对微小结构几何量测量的需求,通过集成MEMS微触觉测头和纳米测量机构建了高精度的测量系统.在验证测头性能的基础上,完成了一系列判断测头测量分辨力和精度的实验,在轴向、同向横向、异向横向三个方向测量的标准偏差分别为41.755 2 nm,6.05 μm,6.16μm,同时,在扫描实验中进程回程扫描差值的标准偏差为23.088 nm.     

Aversive textures and their role in food rejection

Texture is a prominent feature in foods and consequently can be the reason a food is accepted or rejected. However, other sensory attributes, such as flavor/taste, aroma, sound, and appearance may also lead to the rejection of food and motivations other than unpleasantness exist in unacceptance. To date, these motivations for food rejection have been studied in isolation and their relationships with psychological factors have not been tested. This study measured reasons people reject a food and probed into the specifics of texture rejection. A large U.S. sample (N = 473) was asked to rate their motivations for rejecting a food, list foods that were disliked due to unpleasant sensory attributes, specify the unpleasant sensory attribute(s), and complete an assessment of general touch sensitivity. Results showed 94% of individuals reject a food due to its texture, a rate comparable to flavor-based rejection. Looking at the number of foods being rejected, flavor was the most common food attribute, followed by texture and then aroma. From a linguistic standpoint, aversive textures encompass a large vocabulary, larger than liked textures, and the same food may be rejected due to a single or combination of texture terms. Viscosity (e.g., slimy) and hardness (e.g., mushy) are the most common aversive texture types, but through cluster analysis subsets of individuals were identified that are more aversive to other textures. This study emphasizes the role of aversive textures in food rejection and provides many avenues for future investigations.     

Enhanced Sensitivity of Iontronic Graphene Tactile Sensors Facilitated by Spreading of Ionic Liquid Pinned on Graphene Grid

Iontronic graphene tactile sensors (i‐GTS) composed of a top floating graphene electrode and an ionic liquid droplet pinned on a bottom graphene grid, which can dramatically enhance the performance of capacitive‐type tactile sensors, are presented. When mechanical stress is applied to the top floating electrode, the i‐GTS operates in one of the following three regimes: air–air, air–electric double layer (EDL) transition, or EDL–EDL. Once the top electrode contacts the ionic liquid in the i‐GTS, the spreading behavior of the ionic liquid causes a capacitance transition (from a few pF to over hundreds of pF). This is because EDLs are formed at the interfaces between the electrodes and the ionic liquid. In this case, the pressure sensitivity increases to ≈31.1 kPa^?1 with a gentle touch. Under prolonged application of pressure, the capacitance increases gradually, mainly due to the contact line expansion of the ionic liquid bridge pinned on the graphene grid. The sensors exhibit outstanding properties (response and relaxation times below 80 ms, and stability over 300 cycles) while demonstrating ultimate signal‐to‐noise ratios in the array tests. The contact‐induced spreading behavior of the ionic liquid is the key for boosting the sensor performance.