M.-Y. Cheng

A flexible capacitive tactile sensing array with floating electrodes

In this work, we present the development of a capacitive tactile sensing array realized by using MEMS fabrication techniques and flexible printed circuit board (FPCB) technologies. The sensing array, which consists of two micromachined polydimethlysiloxane (PDMS) structures and a FPCB, will be used as the artificial skin for robot applications. Each capacitive sensing element comprises two sensing electrodes and a common floating electrode. The sensing electrodes and the metal interconnect for signal scanning are implemented on the FPCB, while the floating electrode is patterned on one of the PDMS structures. This special design can effectively reduce the complexity of the device structure and thus makes the device highly manufacturable. The characteristics of the devices with different dimensions are measured and discussed. The corresponding scanning circuits are also designed and implemented. The tactile images induced by the PMMA stamps of different shapes are also successfully captured by a fabricated 8 × 8 array.

Tactile and shear stress sensing array using capacitive mechanisms with floating electrodes

This work presents the development of a capacitive tactile and shear-stress sensing array which can be easily and reliably fabricated by using MEMS techniques and flexible printed circuit board (FPCB) technologies. The sensing array consists of two micromachined PDMS structures and an FPCB with sensing electrodes. Each shear sensing element comprises four capacitive sensing element arranged in 2×2 array, and each capacitive sensing element has two sensing electrodes and a common floating electrode. The proposed design can effectively reduce the complexity of the capacitor structure without compromise in sensitivity.

A flexible tactile sensing array based on novel capacitance mechanism

In this work, we present the development of a reliable capacitive tactile sensing array by using simple fabrication processes. The sensing array, which consists of aN micromachined PDMS structure and a flexible printed circuit board with sensing electrodes, will be mainly used as the artificial skin for robot applications. The proposed design can effectively reduce the complexity of the capacitor structure of each sensing element without compromise in sensitivity. The electrical properties of different size of tactile sensing elements are measured. The corresponding scanning circuit is also implemented. The tactile images induced by the PMMA stamps of different shapes have been successfully captured.

Flexible Temperature Sensor Array using Electro-Resistive Polymer Forhumanoid Artificial Skin

This paper presents a novel method to fabricate temperature sensor arrays by dispensing electro-resistive polymer on flexible polyimide films. The sensor array can be used as humanoid artificial skin for sensation system of robots. Polydimethlysiloxane (PDMS) was used as the matrix of the electro- resistive composites and different conductive fillers such as carbon black, graphite powder, carbon nano- fibrils have been investigated. It was found that graphite powder serves as the best conductive filler for highest temperature sensitivity and better stability. The volume fraction of the graphite powder for large dynamic range from 20degC to 100degC has been investigated and was found to be 20%. The detected temperature contours are in well agreement with the shapes and magnitudes of different heat sources.

A wireless flexible temperature and tactile sensing array for robot applications

The development of a flexible 8x8 temperature and tactile sensing array, which will serve as the artificial skin for robot applications, is presented in this work. Pressure conductive rubber is employed as the tactile sensing material, and discrete temperature sensor chips are employed as the temperature sensing cells. Small disks of pressure conductive rubber are bonded on pre-defined interdigital copper electrode pairs which are patterned on a flexible copper-PI substrate which is fabricated by micromachining techniques. This approach can effectively reduce the crosstalk between each tactile sensing element. The mechanical and electrical properties of tactile sensing elements are measured. Also, scanning circuits are designed and implemented. The temperature and tactile sensing elements are heterogeneously integrated on the flexible substrate. By using the integrated 8x8 sensing arrays, temperature and tactile images induced by the heaters/stamps of different shapes have been successfully measured. Radio-frequency (RF) wireless modules are also developed and integrated on the skin system.

A flexible tactile sensing array for robot applications

This work presents the development of a reliable capacitive tactile sensing array which will be tailored as the artificial skins for a humanoid robot. The proposed capacitive sensing element include of two sensing electrodes and a common floating electrode. The sensing electrodes as well as the metal interconnect for signal scanning are implemented on the FPCB, while the floating electrode is patterned on one of the PDMS structures. This special design can effectively reduce the complexity of device structure and thus makes the device highly manufacturable. The measured maximum sensitivity is about 14.5%/kPa. Pressure distribution is captured using a scanning circuit. The deployment of the skin on a humanoid robot is also demonstrated.