Measurement Techniques with Frequency-Modulated Probe Light for Proximity and Tactile Combo Sensor

Abstract

We have developed a single sensor which can detect proximity and multi-axial touch force for smart-manipulation control of delicate objects. In this work, a measurement technique with modulated probe light to reduce of the environmental noise for proximity sensing has been reported. The white LED as probe light was switched at 150 Hz. Although the sensor output includes environmental noise from power source and room light, it is demonstrated that the proximity distance can be distinguished as amplitude of frequency component at 150 Hz.

Miniaturization and High-Density Arrangement of Microcantilevers in Proximity and Tactile Sensor for Dexterous Gripping Control

“…Therefore, in this work, we aim to (1) reduce the size of the cantilever; and (2) place the cantilevers more densely. Furthermore; (3) an interdigitated array electrode (left part of Figure 1) is newly designed to improve the sensitivity as proximity sensor [18]. The pattern of the new sensor was designed using IC layout CAD (LayoutEditor, juspertor GmbH, Unterhaching, Germany).…”

“…In previous works, the light is detected as impedance between wiring electrodes [16,17]. It is found that contribution of depletion layer capacitance to light sensitivity is larger than that of resistance in the Si layer [18], however, effect of resistance in the Si layer is comparably large because of gap between wiring electrodes (>100 μm). Therefore, to decrease the gaps between electrodes and effect of resistance, we employ interdigitated array electrodes with narrow gaps in this work.…”

“…In addition, the interdigitated electrode array has mesh holes to increase the amount of incident light on Si. This is because it has been demonstrated that light sensitivity can be enhanced by forming a lot of mesh holes [18]. …”