CN-121994385-A - Bionic flexible touch sensor based on optical fiber MZ interference and preparation method thereof

CN121994385ACN 121994385 ACN121994385 ACN 121994385ACN-121994385-A

Abstract

The invention discloses a bionic flexible touch sensor based on optical fiber interference and a preparation method thereof. The sensor comprises a Mach-Zehnder interference type optical fiber sensor formed by dislocation fusion of single-mode optical fibers and a bionic flexible packaging structure for bearing the optical fiber sensor. When external tactile force acts on the bionic octopus sucker array, the bionic flexible packaging structure cooperatively deforms, the deformation is effectively transferred to a medium area around the optical fiber through a porous structure, and the medium equivalent refractive index change is caused, so that the phase difference of the optical fiber Mach-Zehnder interference structure is modulated, the optical fiber interference sensor is expressed as the change of interference light intensity in a spectrum analyzer, and the optical detection of weak tactile force is realized. The invention has simple structure, high flexibility and strong electromagnetic interference resistance, and the preparation process is based on the conventional molding method, has feasibility of array and batch preparation, and has good application prospect in the fields of flexible touch perception and fine force detection.

Inventors

SHEN CHANGYU
YANG YUNYUN
ZHANG SHUNHANG
REN YIMING
JIN YONGXING
DONG JIE
YANG FAN

Assignees

中国计量大学

Dates

Publication Date: 20260508
Application Date: 20260320

Claims (1)

1. A bionic flexible touch sensor is composed of an optical fiber MZ interference sensor (1) and a bionic flexible packaging structure (2), and is characterized in that the bionic flexible packaging structure (2) is composed of a first bionic animal octopus sucker array (21) and a second bionic animal octopus sucker array (22) which are vertically symmetrical, the optical fiber MZ interference sensor (1) is arranged between the first bionic animal octopus sucker array (21) and the second bionic animal octopus sucker array (22) to form a sandwich type bionic flexible touch sensor, the optical fiber MZ interference sensor (1) is a Mach-Zehnder interference structure formed by a first single mode optical fiber (51), a second single mode optical fiber (52) and a third single mode optical fiber (53) through dislocation welding, and the length of the second single mode optical fiber (52) ranges from 3cm to 10cm; A first supporting optical fiber (31) and a second supporting optical fiber (32) are paved on two sides of the optical fiber MZ interference sensor (1), and the first supporting optical fiber (31) and the second supporting optical fiber (32) are paved in parallel with the optical fiber MZ interference sensor (1) to provide mechanical supporting and limiting functions for the optical fiber MZ interference sensor (1); The preparation molds of the first bionic animal octopus sucking disc array (21) and the second bionic animal octopus sucking disc array (22) are prepared by a 3D printing technology, and the molds are used for limiting the space morphology of the bionic sucking disc array; the first bionic animal octopus sucking disc array (21) and the second bionic animal octopus sucking disc array (22) are prepared through a sugar particle sacrificial template pore-forming method, an open-cell foam structure is formed in the first bionic animal octopus sucking disc array and the second bionic animal octopus sucking disc array (22) in a mutually communicated mode, so that the capability of changing contact media between the bionic flexible packaging structure and the optical fiber MZ interference sensor (1) under a pressed state is enhanced, the first bionic animal octopus sucking disc array (21) and the second bionic animal octopus sucking disc array (22) are of an array distribution structure, the array arrangement mode is n multiplied by m, the range of n is 2 to 10, the range of m is 2 to 10, and when external tactile force is applied to the first bionic animal octopus sucking disc array (21) and the second bionic animal octopus sucking disc array (22), the bionic flexible packaging structure (2) deforms, and the equivalent refractive index of a surrounding medium of the optical fiber MZ interference sensor (1) is changed, so that the optical fiber MZ interference sensor (1) outputs interference change, and the external tactile force is detected.

Description

Bionic flexible touch sensor based on optical fiber MZ interference and preparation method thereof Technical Field The invention relates to the technical field of flexible touch sensing, in particular to a bionic flexible touch sensor based on a refractive index modulation mechanism and a preparation method thereof, and belongs to the technical crossing field of optical fiber sensing and flexible touch sensors. Background With the development of intelligent perception technology, touch sensing has important application value in the fields of robot operation, medical rehabilitation, precise perception and the like. In the existing touch sensing technology, part of schemes rely on electrical parameter changes to realize signal detection, and the sensing modes usually need to introduce conductive materials or circuit structures, are easily affected by electromagnetic interference in a complex environment, and are limited in signal stability and sensitivity under a weak force detection scene. In order to overcome the problems, the optical signal-based touch sensing technology is focused gradually, the optical fiber sensor has the advantages of strong electromagnetic interference resistance, stable signal transmission, suitability for remote detection and the like, is suitable for touch sensing in complex environments, and the conventional optical fiber touch sensing scheme mainly causes axial strain, bending or deformation of an optical fiber through external force action, so that the optical signal is changed, however, the sensing mode usually needs larger mechanical deformation to generate obvious optical response, and has limited detection sensitivity under the condition of tiny pressure or weak touch stimulus. On the other hand, in order to improve the response capability of the touch sensor to weak external force, part of researches are conducted to introduce a bionic microstructure to realize the concentration and amplification effects on external pressure, such as simulating the design of a biological adsorption structure or a surface microstructure, but the existing bionic structure is mostly concentrated in the field of electric touch sensing, and in the optical fiber sensing technology, how to effectively combine a bionic flexible structure with an optical sensing mechanism so that the external micro pressure directly modulates an optical signal through medium change, and still lacks a mature scheme. Therefore, there is a need for a tactile sensing scheme based on the optical fiber sensing principle and combined with a bionic flexible structure without electrical components, so as to realize stable and sensitive optical tactile detection under the action of weak external force. Disclosure of Invention The invention mainly aims at the problems that the conventional touch sensor is difficult to realize high-sensitivity and stable detection under the action of weak force and is difficult to effectively amplify touch response while keeping flexibility, and provides a flexible touch sensor based on a single-mode fiber dislocation fusion welding interference structure and a flexible packaging structure, wherein the sensor is formed by embedding the single-mode fiber dislocation fusion welding optical fiber Mach-Zehnder interference structure in a porous Ecoflex flexible substrate with a bionic flexible packaging structure (2), so that the external touch pressure can cause the refractive index change of a medium around an optical fiber, thereby representing the change of interference light intensity in a spectrum analyzer to realize the detection of the weak touch force, and the preparation method at least comprises the following steps: S1, preparing a single-mode optical fiber dislocation fusion interference sensor; s2, preparing a bionic flexible packaging structure (2) based on a sugar particle sacrificial template; S3, assembling the flexible touch sensor and connecting the detection device. The optical fiber MZ interference sensor (1) in the step S1 is formed by sequentially and misplaced welding a first single-mode optical fiber (51), a second single-mode optical fiber (52) and a third single-mode optical fiber (53), and adjacent single-mode optical fibers are led in transverse offset in the welding process so as to form modal coupling in a welding area, so that an optical fiber Mach-Zehnder interference structure is formed. Preferably, the length of the single mode optical fiber between the two dislocated fusion regions is in the order of centimeters, for example in the range of 3-10 cm. The sensitivity of the optical fiber sensor to the change of the refractive index of the surrounding medium can be improved while the definition of interference fringes is ensured in the range. In the step S2, the bionic flexible packaging structure is used for coating and carrying the optical fiber MZ interference sensor (1) prepared in the step S1, so that external tactile force can be transmitted to a medium around