Construction And Front-edge Cross-application Based On New High-performance Tactile Sensor Devices

The robot intelligent electronic skin is a large-area,flexible,and close-fitting flexible electronic system that can obtain physical stimuli to the distributed sensor array and preprocess the sensor signals.It is transparent,scalable,and multifunctional.It can qualitatively and quantitatively perceive the changes of external physical stimulus signals,which is an important form of realizing the tactile function of robots.Based on the efforts of the past ten years,through various sophisticated strategies,the development of tactile sensor electronic skin has made great progress.However,due to the difficulties of design and preparation technology,most flexible tactile sensors are still in the experimental discussion stage.There are still many core restrictive problems that need to be solved urgently.Related research is still in its infancy and cannot realize valid intelligent applications.This article designed and constructed field-effect transistors(FETs)with superior performance and novel structures,enhanced piezoelectric tactile sensors,and three-dimensional graphene interconnected microchannel piezoresistance in response to the performance limitations of piezoelectric and piezoresistive tactile sensors.It has been explored and researched on its application in flexible wearable signal monitoring and other aspects.Aiming at the bottleneck problem that piezoelectric sensors have high sensitivity but weak force-to-electric conversion signals of piezoelectric nanomaterials,which are easily submerged in noise,we use nano-scale flexible piezoelectric sensing principles and material design and use FET devices to detect piezoelectric signals.The coupling enhances the force-electricity conversion signal to obtain a high-sensitivity piezoelectric pressure sensing unit.The force-toelectric conversion effect mediated by piezoelectric materials is the basis for pressure sensing.To achieve signal amplification and improve sensor signal output,we have fabricated a precision device.A bottom-gate top contact organic field-effect transistor(OFET)serves as a signal output terminal.In this way,the influence of piezoelectric discharge on the transport performance of FET semiconductors was studied.By adjusting the gate voltage of the FET,the amplification mechanism of the force-electric coupling effect of the nanorod array was mastered,and the pressure test limit,sensitivity,FET magnification,and other in-depth research.Finally,integrating the FET-enhanced piezoelectric tactile sensor on the PET substrate can monitor the wrist's bending angle in real-time and present an excellent linear relationship.This work is expected to solve critical scientific issues and technical bottlenecks in tactile sensor sensitivity,reliability,stability,batch preparation,etc.It is expected to provide an intelligent electronic skin for robotic systems and provide theoretical basis and technical support for application demonstrations.The above mentioned FET piezoelectric sensor is not easy to achieve high integration in the space structure due to the device's design and distribution.In contrast,the piezoresistive sensor has a simple form and makes it easier to prepare a large-area array matrix.The piezoresistive sensor's active material is more abundant and flexible,and the resistance change under the action of external force is more sensitive,so it has a broader application prospect.However,the deposited active layer properties are different within the same batch,and the microstructure and functions of the materials of various collections are also very different.This variability is the main reason why the simple design of the piezoresistive sensor has not been successfully applied in practice.Piezoresistive sensors using flexible polymers as substrates and graphene and its derivatives as conductive materials can overcome the shortcomings of pressure sensors on rigid substrates.Flexible composite materials containing graphene are considered to be the most promising sensing materials for next-generation wearable sensors.In this regard,we propose a method for fabricating a susceptible strain and pressure sensor based on self-assembled three-dimensional interconnected graphene microchannels of gold nanoparticles embedded in PDMS.The performance of the active layer generated by this method is very stable.First,a multi-layer graphene nano-film is deposited on the foamed nickel by a chemical vapor deposition(CVD)method to form a graphene-coated foamed nickel sheet.The freshly mixed PDMS solution is spin-coated,vacuum treated,and cured to fill the porous nickel foam evenly.The nickel framework was chemical etching to obtain a three-dimensional network of graphene microchannels embedded in PDMS film(GMC-PDMS).Finally,the gold nanoparticles synthesized by a chemical water bath are self-assembled on the GMC-PDMS membrane's inner wall to form the Au NPs-GMC-PDMS membrane.Due to the high conductivity and mechanical strength of multi-layer,high-quality graphene and the contribution of gold nanoparticles to the microchannel,our device exhibits excellent pressure and strainsensing properties.We demonstrated this material by evaluating the sensing capabilities of pressure-strain sensing devices and real-time monitoring of human pulse and pipeline expansion and object shape recognition based on sensor arrays.This method of preparing highperformance pressure and strain sensors will provide technical support for artificial intelligence,medical testing,wearable devices,and other fields.Finally,the exploration and research of new high-performance tactile sensors in this thesis provide an essential theoretical and experimental basis for its application in the field of nextgeneration wearable devices and electronic skin.