Micro 3D printing of a functional MEMS accelerometer

Abstract

Microelectromechanical system (MEMS) devices, such as accelerometers, are widely used across industries, including the automotive, consumer electronics, and medical industries. MEMS are efficiently produced at very high volumes using large-scale semiconductor manufacturing techniques. However, these techniques are not viable for the cost-efficient manufacturing of specialized MEMS devices at low- and medium-scale volumes. Thus, applications that require custom-designed MEMS devices for markets with low- and medium-scale volumes of below 5000–10,000 components per year are extremely difficult to address efficiently. The 3D printing of MEMS devices could enable the efficient realization and production of MEMS devices at these low- and medium-scale volumes. However, current micro-3D printing technologies have limited capabilities for printing functional MEMS. Herein, we demonstrate a functional 3D-printed MEMS accelerometer using 3D printing by two-photon polymerization in combination with the deposition of a strain gauge transducer by metal evaporation. We characterized the responsivity, resonance frequency, and stability over time of the MEMS accelerometer. Our results demonstrate that the 3D printing of functional MEMS is a viable approach that could enable the efficient realization of a variety of custom-designed MEMS devices, addressing new application areas that are difficult or impossible to address using conventional MEMS manufacturing.

3D Printing by Two‐Photon Polymerization of Polyimide Objects and Demonstration of a 3D‐printed Micro‐Hotplate

“…Micro‐hotplates are used in several applications, including gas sensing, [ 31 ] biochemistry, [ 32 ] and wearable devices. [ 33 ] To realize a functional 3D‐printed micro‐hotplate, we used an approach that combines micro 3D printing of shadow‐masking structures with undercut cross‐sections and subsequent directional metal deposition to form electrically addressable transducers, [ 20 ] i.e., the electrical heaters of the 3D‐printed micro‐hotplate ( Figure a–c). We designed the micro‐hotplate to have two contact electrodes connected to a wire featuring the typical meander shape used for metal lines on flexible substrates.…”

“…The self-shadow masking mechanism of the hotplate design ensured the electrical isolation of the contact electrodes and the heating wire from the substrate (Figure 4c,f). [20] We used platinum as a heater material because of its advantages for high-temperature applications, such as high degradation temperature in air [30] and the linear change of its resistance over temperature. [36] We used a Source Measure Unit 6240B (ADCMT, Japan) to drive the micro-hotplate by forcing a current through the thin film platinum wire (resistive heater).…”

“…Micro 3D printing by two‐photon polymerization can achieve sub‐micrometer resolution [ 16 ] and has been widely used for realizing complex geometries [ 17 ] and a variety of devices, including photonic crystals, [ 18 ] biomedical scaffolds, [ 19 ] and MEMS devices. [ 20 ] However, the photosensitive polymers used in these approaches have limited temperature stability and micro 3D printing of polyimide structures by two‐photon polymerization has to the best of our knowledge not been reported in the literature. Micro 3D printing by two‐photon polymerization of temperature‐stable inorganic materials has been achieved previously using sintering of 3D‐printed composite materials [ 21 ] and by direct 3D printing of silica glass.…”

Four-Dimensional Printing of a Fiber-Tip Multimaterial Microcantilever as a Magnetic Field Sensor

“…Magnetic sensors are widely used in power systems, , magnetic navigation, space science, controllable nuclear fusion, mineral exploration, medical diagnosis, − and other fields. , With the “Lab on Fiber” technology developing further, optical fiber sensors have been widely applied in magnetic sensing , due to their immunity to electromagnetic interference, miniaturized structure, high sensitivity, quick response, and the potential for remote sensing . The optical fiber end facets are inherently extensible platforms for multifarious micro- and nano-optical sensing structures. − Femtosecond (Fs) laser-induced two-photon polymerization (TPP) is a three-dimensional (3D) printing technology with nanometer resolution, widely used to print polymer micro- and nanostructures of an arbitrary shape. ,− With the advantages of high integration and short response time, the fiber-tip polymer microcantilever sensors have been widely used for highly sensitive measurement of microforce, , hydrogen, , organic solvent, and microfluid . After being functionalized with magnetically responsive materials, the fiber-tip polymer microcantilever is expected as a highly sensitive magnetic sensor.…”

Additive Manufactured Strain Sensor Using Stereolithography Method with Photopolymer Material

“…Sensors and actuator systems in macro [ 19 ], micro [ 20 , 21 ], and nano [ 22 ] sizes can be fabricated with AM. Different 3D printing techniques have been developed for the fabrication of these systems.…”