Periodic Reporting for period 3 - 5D NanoPrinting (Functional & Dynamic 3D Nano- MicroDevices by Direct Multi-Photon Lithography)
Okres sprawozdawczy: 2023-03-01 do 2025-02-28
In the 5DNanoPrinting project we aim to develop a novel and functional approach for the fast and inexpensive prototyping of functional 3D Microelectromechanical systems - MEMS. Comparable to the disruptive effect of 3D manufacturing technologies in the last decade, thanks to our approach we aim to set a novel gold standard for the fabrication of micro and nanotechnologies, which combine an unprecedented structural freedom with the possibility of employing a vast plethora of materials with different properties and characteristics. In doing so, the 5DNanoPrinting project aspire to produce innovative solutions to express the full potential of MEMS devices, a process whose development, despite the immense progress made in the past fifteen years, is still time-consuming and expensive.
New methodologies for 3D rapid prototyping can overcome these limitations, speeding up the design and validation process, but also broaden the scope of microfabrication to include structures and functionalities which are not achievable with standard methods. To achieve so, during the project, we are developing a multifunctional platform that enables the integration of arbitrary structures with sub-micrometric resolutions and (dynamic) functionalities.
Novel functional materials compatible with two-photon lithographic techniques (aka Direct Laser Writing, DLW) are currently being developed that comprise graded structural, patternable, conductive, and stimuli-responsive materials – which constitute the minimum set of requirements to create a complete functional MEMS. By combining these latter, with as well other established lithographic techniques and components, we already started to investigate the possibility of realizing working 3D-printed MEMS which can be interfaced with current technologies. The ambition of the 5D NanoPrinting is to become a novel gold standard for micro/nano-technologies, thus impacting on European scientific and industrial
New methodologies for 3D rapid prototyping can overcome these limitations, speeding up the design and validation process, but also broaden the scope of microfabrication to include structures and functionalities which are not achievable with standard methods. To achieve so, during the project, we are developing a multifunctional platform that enables the integration of arbitrary structures with sub-micrometric resolutions and (dynamic) functionalities.
Novel functional materials compatible with two-photon lithographic techniques (aka Direct Laser Writing, DLW) are currently being developed that comprise graded structural, patternable, conductive, and stimuli-responsive materials – which constitute the minimum set of requirements to create a complete functional MEMS. By combining these latter, with as well other established lithographic techniques and components, we already started to investigate the possibility of realizing working 3D-printed MEMS which can be interfaced with current technologies. The ambition of the 5D NanoPrinting is to become a novel gold standard for micro/nano-technologies, thus impacting on European scientific and industrial
The work carried out targeted three of the main specific objectives of the 5D NanoPrinting project:
I. Fabrication of a multi-photon, multi-parametric fabrication-testing system that has been used to assess functionality and run-time control of 2γ polymerization on our developed materials. The system will be able to simultaneously provide femtosecond pulsed beam (for two photon lithography), and additional stimuli in order to finely modulate materials properties at polymerization stage. The system up and running and Optimization has been performed to expand the fabrication capability beyond the two photon polymerization.
II. Development of a portfolio of new materials, suitable for two photon lithography and 3D polymerization with sub-micrometric resolution, having the following functionalities:
- Graded mechanical properties (materials that can be spatially modulated in terms of stiffness tensor).
Several approaches have been investigated, and two of them fulfil the targeted characteristics
- Conductivity (materials that can be shaped to provide conformal 3D electric patterns and connections).
Several approaches have been investigated for both electronic a ionic conductions. two of them fulfil the targeted characteristics
- Mechanical responsiveness (for creating micro- nano-actuation components).
Also in this case, several approaches have been investigated, including the use of liquid crystalline elastomers aligned using several methods, and thermos-pneumatic actuation. The latter approach mostly fulfil the planned the targeted indicators. Another materials based on hydrogel composition, working in liquid environment, has been proven to be highly effective as controllable actuation.
- Electrical responsiveness to mechanical stimuli for sensing.
Materials with piezoresistive and piezoelectric capability, compatible with two photon approach has been investigated. One of them fulfil the targeted specification.
III. Proof-of-concept functional MEMS printed via DLW. We fabricated a working accelerometer based on a 3D microprinted design as first proof of concept. Moreover, a preliminary prototype of cochlear implant has been investigated as proof of the approach and integration of the different materials and technologies investigated in 5D NanoPrinting. Finally, a novel technique to integrate standard processes and devices with DLW has been developed.
I. Fabrication of a multi-photon, multi-parametric fabrication-testing system that has been used to assess functionality and run-time control of 2γ polymerization on our developed materials. The system will be able to simultaneously provide femtosecond pulsed beam (for two photon lithography), and additional stimuli in order to finely modulate materials properties at polymerization stage. The system up and running and Optimization has been performed to expand the fabrication capability beyond the two photon polymerization.
II. Development of a portfolio of new materials, suitable for two photon lithography and 3D polymerization with sub-micrometric resolution, having the following functionalities:
- Graded mechanical properties (materials that can be spatially modulated in terms of stiffness tensor).
Several approaches have been investigated, and two of them fulfil the targeted characteristics
- Conductivity (materials that can be shaped to provide conformal 3D electric patterns and connections).
Several approaches have been investigated for both electronic a ionic conductions. two of them fulfil the targeted characteristics
- Mechanical responsiveness (for creating micro- nano-actuation components).
Also in this case, several approaches have been investigated, including the use of liquid crystalline elastomers aligned using several methods, and thermos-pneumatic actuation. The latter approach mostly fulfil the planned the targeted indicators. Another materials based on hydrogel composition, working in liquid environment, has been proven to be highly effective as controllable actuation.
- Electrical responsiveness to mechanical stimuli for sensing.
Materials with piezoresistive and piezoelectric capability, compatible with two photon approach has been investigated. One of them fulfil the targeted specification.
III. Proof-of-concept functional MEMS printed via DLW. We fabricated a working accelerometer based on a 3D microprinted design as first proof of concept. Moreover, a preliminary prototype of cochlear implant has been investigated as proof of the approach and integration of the different materials and technologies investigated in 5D NanoPrinting. Finally, a novel technique to integrate standard processes and devices with DLW has been developed.
The work carried out brought to the publication of 28 scientific papers and 2 deposited patents, one on a new erasable material for Direct Laser Writing, and another one on Laser Induced Graphene. The main concepts related to the technologies developed within the 5D NanoPrinting project have been presented during a specific open Tutorial meeting event, which presentations are available on the web site of the project.
Specifically, a significative progress beyond the state of the art has been reached in this project on several of the materials developed. In particular, the aspect that has been addressed successfully are the following:
- Development of a new erasable material for DLW: the work on this specific material is now successfully concluded. This material formulation is completely new and can be used by DLV to build 3D structures with very high resolution; Moreover it can be removed with in very mild conditions. One patent related to this has been deposited and a scientific paper has been published.
- Development of new actuations materials based on aligned liquid crystal elastomer (LCE) Compatible 3D DLW. Different approaches advancing the state of the art of the field has been demonstrated. Two scientific paper on this topic have been published.
- Development 3D DLW patternable Ionogels for optical sensing of gases. In this case the fabrication of photonic crystal starting form different ionogel formulation has been demonstrated for the first time. The results have been published on a couple of scientific papers.
- A technique to create electric path on 3D DLW structure has been also proposed and validated on a significative demonstrative device. In particular, the technique has been used to built directly in two step (DLW plus metal evaporation) a simple but working monoaxial accelerometer, with piezoresistive transduction. The result has been presented to a conference and the related scientific paper on the proceeding of the same conference.
- A Technique for easy handling and conformal transfer transfer of 3D 2PP micro-structures has been developed. The results have been published on a published scientific paper.
- A demonstrative application of the technique of transfer of 3D 2PP micro-structures has been applied to implement THz meta-surfaces. The results have been published on a published scientific paper.
- A Technique for lateral etching of silicon, compatible with standard MEMS fabrication processes has been developed.
- Advancements on Laser Induced Graphene and integration with 2PP processes have been reached. The results have been published on a scientific paper.
- Several proof-of-concept of functional devices printed via DLW has been achieved to demonstrate the integration of the different materials and technologies investigated in 5D NanoPrinting. These results will be published on a scientific paper.
Specifically, a significative progress beyond the state of the art has been reached in this project on several of the materials developed. In particular, the aspect that has been addressed successfully are the following:
- Development of a new erasable material for DLW: the work on this specific material is now successfully concluded. This material formulation is completely new and can be used by DLV to build 3D structures with very high resolution; Moreover it can be removed with in very mild conditions. One patent related to this has been deposited and a scientific paper has been published.
- Development of new actuations materials based on aligned liquid crystal elastomer (LCE) Compatible 3D DLW. Different approaches advancing the state of the art of the field has been demonstrated. Two scientific paper on this topic have been published.
- Development 3D DLW patternable Ionogels for optical sensing of gases. In this case the fabrication of photonic crystal starting form different ionogel formulation has been demonstrated for the first time. The results have been published on a couple of scientific papers.
- A technique to create electric path on 3D DLW structure has been also proposed and validated on a significative demonstrative device. In particular, the technique has been used to built directly in two step (DLW plus metal evaporation) a simple but working monoaxial accelerometer, with piezoresistive transduction. The result has been presented to a conference and the related scientific paper on the proceeding of the same conference.
- A Technique for easy handling and conformal transfer transfer of 3D 2PP micro-structures has been developed. The results have been published on a published scientific paper.
- A demonstrative application of the technique of transfer of 3D 2PP micro-structures has been applied to implement THz meta-surfaces. The results have been published on a published scientific paper.
- A Technique for lateral etching of silicon, compatible with standard MEMS fabrication processes has been developed.
- Advancements on Laser Induced Graphene and integration with 2PP processes have been reached. The results have been published on a scientific paper.
- Several proof-of-concept of functional devices printed via DLW has been achieved to demonstrate the integration of the different materials and technologies investigated in 5D NanoPrinting. These results will be published on a scientific paper.