Design Of Photoelectric Effect Based Soft Strain Sensor And Their Application

With the development of technology,smart wearable technology becomes more and more prosperous.Flexible sensors,as a crucial part of smart wearable technology,are getting increasing attentions.Among these sensors,flexible strain sensors are widely used in medical,health,sports,entertainment,industrial and military fields.For the application of the flexible strain sensor on the human body,it can be used to detect the physiological activities of the human body,joint movements,and even facial expressions.It plays a crucial role in human interaction with the outside world.However,high sensitivity,high stretchability,and good stability are still a huge challenge for flexible strain sensors.Therefore,this paper is devoted to proposing a flexible strain sensor with super tensile performance,high sensitivity and high stability.Inspired by the working principle of human eyes,this paper innovatively proposes a flexible strain sensor based on the principle of photoelectric effect.The sensor is composed of a light emitting diode,a silicon photodiode,a sensor shell and a silicone rod.Specifically,the silicone rod converts the change in strain into a change in optical signal,and converts the optical signal into an electrical signal through the photoelectric effect to realize the detection of strain.This article systematically explores the working principle,production process,performance analysis,and wearable applications of strain sensors.The main contents and conclusions are as follows:1.Structural design and principle analysis of flexible strain sensor.First,the sensor is designed based on the photoelectric effect,and the performances of the sensor under different structures are analyzed.Second,the working principle of the sensor and the factors that affect the sensitivity and working range of the sensor are analyzed.It has been found that the sensitivity and working range of the sensor are related to the luminous intensity of the light emitting diode.At high luminous intensity state,the sensor has higher sensitivity and narrower working range;at low luminous intensity state,the sensor has lower sensitivity and wider working range.Besides,the sensitivity and working range of the sensor can be changed by tuning the light intensity of the light emitting diode.At the same time,it also has been found that the diffraction of light can affect the linear performance of the sensor.2.Sensor performance testing and application research.Through experimental tests,the sensor has both high sensitivity and a wide working range.The working range of the sensor is 0-700%,and the maximum sensitivity(GF)of the sensor is 1175.In addition,the sensor also has low drift(±1.2%),high repeatability(remains at the stable state under 5000 times of stretching and releasing)and fast response performance(the response time is about 10ms).In terms of applications,the sensor is tested on human physiological information monitoring(including sleep data,pulse)and human motion information monitoring(including finger and wrist bending angles,and lower limb motion patterns).In addition,the sensor is fabricated into a data glove for detecting the human hand motion.Moreover,a human-computer interaction interface of the data glove is established based on Unity-3D.