Crosstalk‐Free, High‐Resolution Pressure Sensor Arrays Enabled by High‐Throughput Laser Manufacturing

Abstract

Simultaneously achieving high spatial resolution and low crosstalk interference has been a fundamental challenge for flexible pressure sensor arrays. Here the authors present a high-resolution flexible pressure sensor array fabricated through a two-step laser manufacturing process, where individual sensing pixels and their interconnects are sequentially defined by laserinduced graphenization and ablation to minimize crosstalk interferences. The geometry of the interconnects is optimized through theoretical modeling and experimental validation. Characterization results show that the new device design induces a remarkable reduction of the crosstalk coefficient, from −8.21 to −43.63 dB, of the 0.7 mm-resolution sensor arrays, and the crosstalk suppression is particularly beneficial for application scenarios involving pressure sensing on soft surfaces (e.g., human skin and organs). Applications of the sensor array in tactile pattern recognition and minimally-invasive cancer surgery are demonstrated.

Laser Micro/Nano‐Structuring Pushes Forward Smart Sensing: Opportunities and Challenges

“…To achieve high spatial resolution and surmount the crosstalk problem in pressure sensor arrays at low fabrication cost, picosecond laser processing (355 nm, 2.1-6.8 W) was employed by Li's group to create a sensor array with a high resolution of 0.7 mm from a polymeric multi-layer stack. [98] Low and high laser power were jointly used to generate isolated piezoresistive 3D graphene pixels and form an interconnect pattern to connect individual pixels (Figure 4c). The obtained mapping sensor exhibited a high sensitivity of 1.37 kPa −1 , a wide pressure working range of 80 kPa, a fast response time of 20 ms, and good cycle stability.…”

“…Reproduced with permission. [98] Copyright 2022, Wiley-VCH. d) Schematic of experimental setups and processes for ps-DLIP and ps-DLW process, showing well-defined patterns with different textured characteristics on Ti64 and Scalmalloy.…”

“…c) Two-step laser manufacturing process of the piezoresistive material array with the serpentine interconnect using a picosecond laser, showing the maintained surface roughness for good sensing responses and unchanged individual pixels during the bending of the sensor array. Reproduced with permission [98]. Copyright 2022, Wiley-VCH.…”

Machine Learning for Tactile Perception: Advancements, Challenges, and Opportunities

“…Traditionally, after precise calibration on tactile sensors, researchers perform statistical analysis, employ transformation theories, count on physical models or simulations, or utilize other mathematical tools to obtain further information from raw data. [5][6][7][8][9] However, these data processing approaches are inadequate when dealing with complex tactile sensing issues, such as providing rapid responses, analyzing heterogeneous signals, offering accurate sensation judgment, and handling large-scale data analysis. While in other perception and understanding fields like computer vision, speech recognition, and natural language processing, machine learning, an emerging data processing technique, has grown by leaps and bounds and achieved outstanding performance in analyzing enormous data streams quickly.…”

Elastomeric polymers for conductive layers of flexible sensors: Materials, fabrication, performance, and applications

“…[8][9][10] Flexible sensors can be classified into two main categories based on the way in which flexibility is achieved: structural and material. The structural flexibility of sensors is achieved by designing traditional material geometries such as fractal structures, [11] wave geometries, [12] serpentine, [13] and kirigami [14] shapes. Since novel materials and conduction mechanisms have been developed, the realization of flexible sensing from a material perspective is gradually attracting research attention.…”