Highly Sensitive Flexible Modulus Sensor for Softness Perception and Clinical Application

The wearable sensors for softness measuring are emerging as a solution of softness perception, which is an intrinsic function of human skin, for electronic skin and human-machine interaction. However, these wearable sensors suffer from a key challenge: the modulus of an object can not be characterized directly, which originates from the complicated transduction mechanism. To address this key challenge, we developed a flexible and wearable modulus sensor that can simultaneously measure the pressure and modulus without mutual interference. The modulus sensing was realized by merging the electrostatic capacitance response from the pressure sensor and the ionic capacitance response from the indentation sensor. Via the optimized structure, our sensor exhibits high modulus sensitivity of 1.9 × 102 in 0.06 MPa, a fast dynamic response time of 100 ms, and high mechanical robustness for over 2500 cycles. We also integrated the sensor onto a prosthetic hand and surgical probe to demonstrate its capability for pressure and modulus sensing. This work provides a new strategy for modulus measurement, which has great potential in softness sensing and medical application.

The Effect of Sensor Structure and Coplanar Electrode for Capacitive Based Flow Sensor

This paper presents the analysis of the capacitive based flow sensor using computational fluid dynamic (CFD) and mathematical equation approach. The CFD simulations for different types of sensor structure were carried out. Pressure and velocity of the fluid were varied in order to study the hydrodynamic parameter such as displacement and drag force. For the coplanar electrode, width of electrode and half gap between electrodes were varied for capacitive response using mathematical approach. Based on the simulation, the displacement of the dome increases as the pressure increases. The result shows that the most suitable thickness of the dome is 0.1 mm based on the displacement and the strain. Meanwhile for the coplanar electrode, the width and half gap showed a significant effect on the capacitance response.

Relative humidity sensing properties of indium nitride compound with oxygen doping on silicon and AAO substrates

The research used a DC sputtering system to grow indium nitride compound doped oxygen sensing film, which could be applied in the fabrication of relative humidity sensor. In this study, the design of two specific substrates, including silicon substrate and anodic aluminum oxide (AAO) substrate, were of some uses for relative humidity sensor fabrication to enhance the sensitivity. Besides, the influence of different substrates on responsivity was also explored to verify the sensing performances of indium nitride compound doped oxygen element in relative humidity sensor. The resistance response of InN:O sensing device using silicon substrate was better than that using AAO substrate. The RH adsorption and desorption time of InN:O sensing device using silicon substrate were 94 s and 35 s, respectively. The capacitance response of InN:O sensing device using AAO substrate was better than that using silicon substrate. The RH adsorption and desorption times of InN:O sensing device using AAO substrate were 289 s and 286 s respectively.