ITIA-CNR

MEDIS

Micro Enabled Devices and Systems

Research goals

MEDIS

Because things are getting smaller

The group research activities aim at developing innovative technological solutions to ease the adoption of the ‘micro' paradigm both at product and process level. The fabrication and assembly technologies, as well as the design, of truly 3D miniaturized high added value products are addressed.

The group main research objective is the development of methodologies and tools for the conception, design and manufacturing of innovative micro/meso devices, starting from the manufacturing of micro components in metal, ceramic and polymeric materials till the fabrication of complex micro systems, going through the handling, manipulation and assembly of micro components. Moreover, all the related supporting technologies, ie: extrusion, injection, electro-di- scharge machining (EDM), gripping, fixturing and vision, are investigated at different scales.

Research activities

Modelling, simulation in multi-physics domains and characterization. At the micro scale, due to the high surface to volume ratio, the influence of superficial forces becomes significant, overcoming the mass forces. This affects both manufacturing and assembly operations. The phenomena regulating the dispersion of nano particles in a polymeric material during extrusion, as well as the flow of the polymer in the mould during micro injection, are modelled using commercial software combined with ad hoc developed routines. Adhesive forces need to be modelled and included in the design of appropriate handling and assembly strategies. Finally, characterisation and failure analyses of the devices (UTS, fatigue test) are carried out. The results of the models are then integrated and tested in the experimental phases.
Micro manufacturing technologies. The group's laboratory is provided with a few commercial machines for the manufacturing of micro components or mini products with microscopic features, namely a micro Electro Discharge Machine (EDM), a micro injection moulding machine and a micro extruder, that constitute the micro manufacturing section of the Factory for micro production. These technologies are individually investigated as well as considered part of a process chain that starts with the preparation of polymeric blends and ends up with the injected moulded final component (ready to use or to be assembled). The EDM technology is investigated to manufacture complex structures with high aspect ratio, including micro moulds and dies, mini products for medical applications. Moreover, fundamental researches on the machinability of hard and brittle materials, such as hardened steel or titanium and ceramic composites, are carried out. Magnesium alloys and aluminium are studied as well. The micro extrusion technology is investigated towards the compounding of nano powder enhanced polymeric resins, employed for biomedical applications (ie: catheters or stents), including the micro manufacturing of extrusion screws.
The micro injection moulding machine is used to manufacture mini components with microscopic features for applications in the biological, communication and electronics sectors. Moreover, the performance of the injection process as function of the most effective parameters (injection speed, melt and mould temperature, holding time and pressure and cooling time) are analysed for different polymers - particularly suitable for the process and the selected applications due to their flowability and stability (PP, POM, LCP, HDPE, PMMA, PEEK, PC and PPS) in order to optimize the processing condition and achieve the limits of the replication capability.

100µm

Micro nozzle for vacuum
gripper fabricated in hardened
steel by micro EDM

Automated micro assembly. The assembly phase of 3D multi material micro devices is still crucial, affecting up to 60% of the final product cost. Indeed, most of the ‘macro' assembling operations cannot be downscaled and several operations are nowadays still done manually, increasing time and cost of fabrication. Thus, the group has developed a flexible and reconfigurable work-cell for the automatic manipulation of micro components. It integrates a commercial high precision robot with Shoenflies motion, equipped with a multiple camera vision system (eye-to-hand and eye-in-hand architectures) for the automatic detection, measure and inspection of micro parts. A set of 2D and 3D machine vision algorithms have been developed implementing the look and move robot control strategy. Conventional and innovative techniques have been applied to calibrate the end effectors and the cameras and georeference them with respect to the manipulator. Different robotic kinematic structures as well as robot force control strategies will be integrated and developed.
This work cell is implemented in the Factory for micro production in the micro assembly section.
Design, manufacturing and experimental validation of micro grippers. When automatic assembling at the micro scale, new and uncontrolled adhesive effects appear at small scale and have to be included in the design of gripping strategies; on the other side, these effects allow the use of physical principles not suitable for macro components. In this context, some innovative handling systems based on depressure, electrostatic and capillary forces, have been conceived, prototyped and tested in the automatic work cell. Also the release phase, that is critical at the micro scale, has been investigated and addressed. Moreover, smart polymers (EAP) have been investigated as innovative means for actuation/sensing. Force sensing is investigated towards the detection of the micro part on the micro gripper and the exertion of different clamping forces.

Main research projects

REMS
Rete Lombarda di eccellenza per la Meccanica strumentale e Laboratorio esteso, Regione Lombardia (2011-2013)
NET4M
Development of a collaborative network for micro -manufacturing, -assembly and -robotics, FP7-PEOPLE (2011-2015)
BACKOP
Backplane Ottico per Apparati ICT di Alta Capacità, MIUR (2011-2014)
MM&A
Micro Manipulation & Assembly, PRIN2009 MIUR (2011-2013)
ECOIMPATTO
Eco-progettazione di compositi e manufatti ottenuti da plastiche di scarto post consumo, Regione Lombardia (2011-2013)
PLUS
Plastic Lab-on-chips for the optical manipUlation of Single-cells, Progetto Bandiera "La Fabbrica del Futuro" (2013-2014)

Detail of ceramic
Si3N4-TiN scaffold for
hard tissue (bone) reconstruction
machined by micro EDM

key words

Micro Manufacturing; Micro Robotics; Micro Assembly; Micro EDM; Micro Injection Moulding.

Contact

Eng. Ph.D. Irene Fassi - Milano
MEDIS Group responsible
irene.fassi [at] itia.cnr.it
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