A high sensitivity micro-pressure sensor based on 3D printing and screen-printing technologies

Abstract

A 3Dprinted micropressure sensor with high sensitivity is developed in this paper. It is a fully printed pressure sensor fabricated using a combination of digital light processing (DLP) based printing and screenprinting technologies, with the advantages of high manufacturing efficiency and low cost. The pressure sensor consists of a sensor substrate with a circular diaphragm and a Wheatstone bridge on the surface. First, the pressure sensor was theoretically analyzed and then verified using the finite element method (FEM). During fabrication, the sensor substrate was made from a transparent hightemperature resin, which was printed by a DLPbased 3D printer. The resistors and leads of the Wheatstone bridge were made from carbon paste and silver paste, respectively, and printed by screenprinting technology. Then, the resistors were characterized to find the gauge factor and the print consistency between different resistors. Next, the experimental setup was established for the characterization of the pressure sensor. Three loops of pressurization and depressurization from 0 kPa to 2.4 kPa were applied to the pressure sensor continuously, and the output voltage was recorded. The experimental results show that the gauge factor of the carbon resistor is 17.01 ± 1.85, the sensitivity of the sensor is 4.5522 mV/kPa/5 V, the linearity error is 2.077% FS, the hysteresis error is 6.327% FS and the repeatability error is 5.708% FS. Also, it is very convenient to obtain pressure sensors with different sensitivities and measurement ranges by changing the thickness of the circular diaphragm. All these results prove that the proposed sensor provides a low cost and high sensitivity approach for micropressure measurement, and that 3D printing can be applied to the production of personalized sensors.

Advances in Printing and Electronics: From Engagement to Commitment

“…The proposed sensor exhibited a sensitivity of 4.6 mV/kPa/5V with a thickness of carbon resistors ≈7 µm, being tunable by changing the resistors’ dimensions. [ 347 ]…”

“…The proposed sensor exhibited a sensitivity of 4.6 mV/kPa/5V with a thickness of carbon resistors ≈7 µm, being tunable by changing the resistors' dimensions. [347] When DLP is combined with direct ink writing, functional structures and devices can be obtained such as strain sensors based on printed elastomer and conductive wires of silver ink encapsulated in the 3D structures, exhibiting a gauge factor of up to 251 at 2% strain. [348] Further, piezoelectrically-adjustable cells with tailored electromechanical response have been developed for pressure sensing applications through 3D-FDM technique.…”

Structural Engineering in Piezoresistive Micropressure Sensors: A Focused Review

“…The other way for polymers to be used in pressure sensors is cooperating with 3D printing techniques. Liu et al printed a micropressure sensor via digital light processing (DLP) and screen-printing techniques [ 86 ]. The transparent high-temperature resin from Formlabs was solidified by the DLP-based printer to form the sensor substrate, and the piezoresistors were made by screen printing a carbon paste.…”

Mold‐Free Manufacturing of Highly Sensitive and Fast‐Response Pressure Sensors Through High‐Resolution 3D Printing and Conformal Oxidative Chemical Vapor Deposition Polymers

“…However, studies on 3D printing-based pressure sensors are limited in the literature because the printing technique with a resolution comparable to photolithography has not yet been established. Extrusion-based 3D printing processes are commonly used to fabricate functional sensors [31,32,[43][44][45][46][47] and 3D-printed mold by replacing Si, [48] due to the easy deposit of multiple materials. However, the resolution of extrusion-based 3D printing is determined by the nozzle size, typically larger than 100 μm.…”