Development of Fully Flexible Tactile Pressure Sensor with Bilayer Interlaced Bumps for Robotic Grasping Applications

Abstract

Flexible tactile sensors have been utilized in intelligent robotics for human-machine interaction and healthcare monitoring. The relatively low flexibility, unbalanced sensitivity and sensing range of the tactile sensors are hindering the accurate tactile information perception during robotic hand grasping of different objects. This paper developed a fully flexible tactile pressure sensor, using the flexible graphene and silver composites as the sensing element and stretchable electrodes, respectively. As for the structural design of the tactile sensor, the proposed bilayer interlaced bumps can be used to convert external pressure into the stretching of graphene composites. The fabricated tactile sensor exhibits a high sensing performance, including relatively high sensitivity (up to 3.40% kPa−1), wide sensing range (200 kPa), good dynamic response, and considerable repeatability. Then, the tactile sensor has been integrated with the robotic hand finger, and the grasping results have indicated the capability of using the tactile sensor to detect the distributed pressure during grasping applications. The grasping motions, properties of the objects can be further analyzed through the acquired tactile information in time and spatial domains, demonstrating the potential applications of the tactile sensor in intelligent robotics and human-machine interfaces.

Tactile Interaction Sensor with Millimeter Sensing Acuity

“…The diameters of the bump structure in the center pressure sensor and the outer pressure sensor were fabricated to be 400 and 300 μm, respectively. The bump structure improves the pressure sensitivity by localizing the contact stimulus to the pit area [ 38 , 39 ]. As seen in Figure 3 f, the clearly patterned graphene with no ripple and crack was transferred to the underside of the PDMS layer.…”

Flexible Capacitive Pressure Sensor Based on Microstructured Composite Dielectric Layer for Broad Linear Range Pressure Sensing Applications

“…Flexible pressure sensors that are considered as the key component of the electronic skin with the unique ability to detect external pressure/force loads have attracted enhanced attention in recent years due to their widespread applications in health monitoring, wearable electronics, and robotics applications. It is interesting to notice that until now, different sensing mechanisms have been adopted in the literature to develop flexible pressure sensing components, such as piezoresistive [1][2][3], piezoelectric [4], capacitive [5][6][7], and triboelectric [8]. On top of that, during the past decade, numerous studies related to capacitive pressure sensors have been conducted due to their simple structure, facile signal acquisition, and low energy consumption [9].…”

“…Moreover, the fabrication method has significant impact on the characteristics of the composite, and the organic solvent that is usually utilized for dispersion of the nanofillers in composite dielectric materials preparation is ungreen [29]. Consequently, it is of great significance to come up with an environmentally friendly preparation method such as planetary mixing [2,19] or three-roll milling [7] for the polymer-based dielectric composite. In addition, carbon black (CB) and carbon nanotubes (CNTs) are ideal candidate materials to enhance the dielectric property of the PDMS due to their high aspect ratio and high dielectric constant [20,28]; thus, both these two nanofillers should be selected in preparing the dielectric composite to reduce the agglomeration of each single kind of nanofiller and increase the dispersion effect.…”

Recent Development of Flexible Tactile Sensors and Their Applications

“…Besides this, we also have a spinning method that was used to construct fiber structure including electrospinning or wet-spinning [ 22 , 23 ]. We also have some other known methods such as electrodeposition and chemical vapor deposition [ 24 , 25 ].…”