Fabrication And Application Of Conformal Semiconductor Proximity Sensor Based On DNTT Thin-Film

Proximity sensing is a non-contact detection recognition function that can help robots or blinds to identify distance,position,and shape of the obstacles,and can timely feedback the information to avoid unnecessary collisions.It is of great significance in terms of security detection and human-machine interfaces.Traditional proximity sensors do not have a conformal ability due to their large size and rigid materials.And the good conformal ability enables the sensor to maintain close adhesion with curved objects during any deformation,which not only achieves a more comfortable wearing feeling,but also ensures the accuracy of the detection results.In contrast,new capacitive proximity sensors and organic semiconductor proximity sensors are more suitable for portable wearable electronics.The sensing principle of the capacitive proximity sensor is based on the interference of the electric field,which results in target objects to be limited to conductors.The advent of a new type of semiconductor proximity sensor makes up for this deficiency.However,the previous organic semiconductor proximity sensors used PET(polyethylene terephthalate)or rigid Si as the substrate and focused on the research of a single device,which limited the conformal ability,shape recognition and spatial position detection of the device.Aiming at the problems of poor flexibility and single device of current organic semiconductor proximity sensors,a flexible and conformable organic semiconductor proximity sensor with DNTT(Dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene)film as the sensing layer was prepared.The specific work of this article reads as follows:1.Based on the elastic substrate,a DNTT thin film two-terminal organic semiconductor proximity sensor was prepared,and its basic sensing performance was systematically explored.The device can be well adhered onto the human finger,and does not move and fall off with the movement of the finger.Even if the device is attached to a glass hemisphere with a diameter of 2.5 cm,it can still realize the proximity of fingers and plastic rulers.The sensor shows excellent range resolution,and the maximum detection distance is 9 cm.It can work at operating voltages as low as 1 V with ultra-low power consumption.2.Based on the elastic substrate,a DNTT thin film two-terminal organic semiconductor proximity sensor array was prepared,and shape recognition and spatial position detection ability of the device was explored.The sensor array is well conformal onto the 3D crystal balls and human brain model without bubbles and wrinkles.The sensor array can recognize the spatial position change of the finger and the shape of the T,L,and I PET sheets both on the plane and on the curved surface.It shows the potential of our device in identifying the location and shape of obstacles.3.Based on the DNTT thin film,a three-terminal field effect transistor proximity sensor integrating signal conversion and signal amplification was constructed,and its sensing performance was systematically explored.The relationship between the carrier density and the sensing performance of the device was explored based on a hard field effect transistor proximity sensor.A self-supporting and conformable field effect transistor proximity sensor was further prepared.The sensor enables conformal adherence with the glass ball,glass rod,and fingertip.When the device is attached to a glass hemisphere with a diameter of 2.5 cm,it still has good field effect performance and the ability to sense the approach of a finger.