The acoustic field of a linear compressor serves to deliver the compression work to the load, such as the connected cold head of a cryocooler; it plays an equivalently important role as the electrical and mechanical p...The acoustic field of a linear compressor serves to deliver the compression work to the load, such as the connected cold head of a cryocooler; it plays an equivalently important role as the electrical and mechanical parts, especially in the impedance match issue. This paper studies the acoustic impedance characteristics of a linear compressor. The parameters including the current, the piston displacement, the pressure amplitude, the electrical power dissipation, the power factor, the pressure-volumetric (PV) power delivered, and the efficiency are theoretically and experimentally investigated. Different from previous theoretical studies, optimization for the operations away from the resonance is also included. More general optimization results imply relevance between thermoacoustic engines and linear compressors. The predicted results are validated by the experiments performed on a linear compressor with an adjustable resistive-capacitive (RC) acoustic load. The comparisons between the calculations and the measurements are presented and analyzed. The results provide deeper insight into the mechanism of the linear compressor and the impedance match in a cryocooler system.展开更多
With the rapid development of the intelligent technology,flexible sensors have widely applied in wearable electronic products,human-computer interaction,soft robots,health care and other emerging fields.At present,mec...With the rapid development of the intelligent technology,flexible sensors have widely applied in wearable electronic products,human-computer interaction,soft robots,health care and other emerging fields.At present,mechanical sensors are based on resistance or capacitance changes alone to achieve a perceived response to force.Meanwhile the methods of flexible mechanical sensors to improve the sensitivity are mainly micro-structuring of the electrode or dielectric layer,which is a complicated process and less probing of the electrode shape.Therefore,this paper proposes a flexible sensor based liquid metal to measure mechanics through resistive-capacitive coupling.Through testing,we obtained the optimal preparation scheme.We also explored the mechanical properties of the sensor design with different combinations of liquid metal electrode shapes using simulation,and then tested the mechanical properties of the double helix liquid metal sensor prepared according to the model structure.With resistive-capacitive coupling,the sensor can achieve a sensitivity of 0.4653 kPa^(-1) with a response range of 10~343 Pa,and it has good tensile and compressive response,and cyclic stability.This study provides a new structural design direction for the subsequent application of liquid metal in flexible sensing with high sensitivity.展开更多
基金supported by the National Natural Science Foundation of China (No. 51176165)the Open Project Program of the Key Laboratory of Infrared Imaging Materials and Detectors (No. IIMDKFJJ-11-07), China
文摘The acoustic field of a linear compressor serves to deliver the compression work to the load, such as the connected cold head of a cryocooler; it plays an equivalently important role as the electrical and mechanical parts, especially in the impedance match issue. This paper studies the acoustic impedance characteristics of a linear compressor. The parameters including the current, the piston displacement, the pressure amplitude, the electrical power dissipation, the power factor, the pressure-volumetric (PV) power delivered, and the efficiency are theoretically and experimentally investigated. Different from previous theoretical studies, optimization for the operations away from the resonance is also included. More general optimization results imply relevance between thermoacoustic engines and linear compressors. The predicted results are validated by the experiments performed on a linear compressor with an adjustable resistive-capacitive (RC) acoustic load. The comparisons between the calculations and the measurements are presented and analyzed. The results provide deeper insight into the mechanism of the linear compressor and the impedance match in a cryocooler system.
基金supported by Beijing Natural Science Foundation(Grand No.L223017)Foundation of China(12332019,U20A20390)the 111 Project(Project No.B13003).
文摘With the rapid development of the intelligent technology,flexible sensors have widely applied in wearable electronic products,human-computer interaction,soft robots,health care and other emerging fields.At present,mechanical sensors are based on resistance or capacitance changes alone to achieve a perceived response to force.Meanwhile the methods of flexible mechanical sensors to improve the sensitivity are mainly micro-structuring of the electrode or dielectric layer,which is a complicated process and less probing of the electrode shape.Therefore,this paper proposes a flexible sensor based liquid metal to measure mechanics through resistive-capacitive coupling.Through testing,we obtained the optimal preparation scheme.We also explored the mechanical properties of the sensor design with different combinations of liquid metal electrode shapes using simulation,and then tested the mechanical properties of the double helix liquid metal sensor prepared according to the model structure.With resistive-capacitive coupling,the sensor can achieve a sensitivity of 0.4653 kPa^(-1) with a response range of 10~343 Pa,and it has good tensile and compressive response,and cyclic stability.This study provides a new structural design direction for the subsequent application of liquid metal in flexible sensing with high sensitivity.
