Thin Film, Miniaturised Components for Next-Generation Smart Medical Devices and Intelligent Industrial Instrumentation

Acquandas Integrated function components

Complex, next-generation, miniaturised smart medical devices and intelligent industrial instrumentation can now be cost-effectively developed and batch-manufactured with significantly higher mechanical properties, increased integrated device functionality and a longer service life, thanks to revolutionary thin film technology.

Background

Goodfellow and the German technology company Acquandas GmbH have formed a new partnership to offer device manufacturers micro-patterned, 2D and 2.5D integrated multi-function miniaturised components and coatings with superior performance properties. All miniaturised components are custom-designed and manufactured to order from CAD drawings using proven thin film microsystem processes and techniques.

Materials

Miniaturised components can be produced using a range of materials including:

Nitinol (NiTi) and other superelastic or shape memory alloys
Bioresorbable alloys
Magnetic materials
Electrical alloys and insulators

Film characteristics

Films are as thin as 5µm (~0.0002 inch) up to 80µm (~0.0031 inch), with feature resolution of 1-10µm (compared with 15µm ± 5µm for a conventional NiTi film) and with a very high level of purity that results in greatly enhanced fatigue endurance.

Key process interfaces

The proprietary Acquandas microsystem technology and techniques incorporate three key process interfaces:

UV-lithography
Magnetron sputtering
Wet chemical etching

Final stages of the production process are heat treatment and shape setting.

New applications

New application opportunities are many and varied.

In healthcare: for the manufacture of next-generation, self-expanding, biocompatible and bioresorbable implant devices and intelligent medical instruments
In defense, aerospace, automotive, telecommunications, test equipment and manufacturing automation: for shape memory alloy-based electrical actuators for robotic applications; and for the latest microelectromechanical (MEMS) technology to manufacture miniaturised electronic relays, position-sensing linear actuators, micro relays, micro valves and micro pumps

From prototype to high-volume production

Two thin film fabrication modes are available to cover both initial new product development (for prototype and small volume development) and full-scale manufacturing (for high-volume production).

Training available, collaboration welcome

Goodfellow provides customers with FEM and CAD-based design training with this thin film technology and welcomes design development partner collaboration.

Key technical data tables/graph

Available materials for Acquandas Thin Film Technology components

Shape memory alloys	NiTi: superelastic or shape memory NiTiCu Other ternary and quaternary SMAs on request
Bioresorbable alloys	Mg alloys Fe alloys
Metallic elements	Al, Ti, Cr, Cu, Mo, Ag, Au, Ta, Pt, Au, Mo Other metals on request
Magnetic materials	NiFe
Alloys with stable electrical properties	CuNiMn
Insulators	SiO, TiO

Comparative test data: Basic properties of Sputtered Nitinol (NiTi) thin films

	Acquandas Nitinol thin films	Nitinol standard material
Tensile strength	1100 — 1500 MPa	1100 — 1300 MPa
Plateau length	5%	8%
Fatigue Endurance Limit (>10 million cycles at 2% mean strain)	1.5%*	0.5 — 0.6%*
Feature resolution	1 — 10 µm	15 µm±5µm
Thickness & homogeneity	>0.1 µm, <80 µm; ±1% of nominal thickness	>50 µm; ±20% of nominal thickness
Corrosion	>1200 mV Break**	1200 mV Break**

* Comparison of the Fatigue Performance of Commercially Produced Nitinol Samples versus Sputter-Deposited Nitinol; Siekmeyer, Schüßler, Lima de Miranda, Quandt, JMEPEG 23 (2014) 2437

** Nitinol: Tubing versus sputtered film – microcleanliness and corrosion behaviour; Wohlschlögel, Lima de Miranda, Schüßler, Quandt, J. Biomed. Mater Res B Appl Biomater. (2015) 201.

Acquandas facilities on the University of Kiel campus

Miniaturised Nitinol (NiTi) metallic components have been successfully produced by Acquandas down to as thin as 5µm up to 80µm with feature resolution of 1-10µm.

Acquandas 2D and 2.5 D metallic components

2D components

The fabrication of 2D structures is Acquandas base technology. Any 2D design can be chosen within the limits of the technology.

2.5D components

2.5 dimensional structures offer a limited degree of freedom into the third dimension. One layer of Nitinol (NiTi) is deposited on top of another layer of Nitinol. Hence, complex geometries can be created, such as flaps attached to a stent-like structure, cavities as reservoirs for micro-pumps or drug-eluting systems, or surfaces covered with micro-needles. In the case of filter systems, certain parts of a Nitinol component can be several tens-of-microns thick in order to give a desired stiffness to the component, while other parts can be thinner and microporous. 2.5 dimensional structures offer a variety of novel design opportunities that are particularly interesting for next generation medical products.

Acquandas integrated function components

Integrated functionality is a novel field that addresses the need for device miniaturisation while simultaneously increasing the functionality of a device. Integrated circuits can be structured on top of a flexible Nitinol (NiTi) structure. The integrated circuits are insulated from the Nitinol structure with a non-conductive oxide.

Thus, different kinds of electrodes on flexible substrates can be produced. Electrodes can be used for sensing, mapping, stimulation or ablation.

A second application of integrated electrical circuits on top of a Nitinol structure is the local activation of shape memory actuators. Instead of directly heating a complete Nitinol actuator, the actuator can be heated locally with low currents, allowing for precise motion control and fast response times due to fast cooling times.

For additional information, email acquandas@goodfellow.com.