3D Micro-Printing: A new Era for Med-Tech Applications - EPFL
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www.photonicsviews.com
3D Micro-Printing: A new Era
for Med-Tech Applications
How three-dimensional thinking is turning a piece of material into smart medical
devices
Alexander Steimle
Meet us at In recent years, 3D printing has at-
Photonics West tracted increasing attention in many
North Hall industries. From bioprinting of living
Booth 4320 organs to engine and airplane compo-
nents, a variety of 3D printing tech- 3.0 mm
niques are already in use today, mainly
differentiated by the additive or sub-
tractive manufacturing approach. But
what’s the application potentiality in
the med-tech industry with regards to
3D printing at micro-scale? And how Fig. 1 Safe puncture tool made of a single glass substrate (Source: Instant Lab & Galatea Lab)
innovative three-dimensional think-
ing can tackle human diseases such as cording to a McKinsey report [1], 100 to factors for device functionalization.
the retinal vein occlusion (RVO) and 200 billion US dollars per year could be The FEMTOPRINT technology is a
create transformative products? generated from direct manufacturing by pioneering subtractive manufacturing
2025, especially in markets with com- technique, Prism Award finalist in 2015
The prospect of machines that can print plex, low-volume and highly customiz- among others. It is based on a two-step
objects the same way an inkjet printer able parts such as medical implants, with process of ultrashort-pulsed laser radi-
creates images on paper, or like ancient elimination of tooling costs, reduction ation in transparent materials, followed
Greek sculptors used a chisel to create in wasted material and handling costs. by chemical wet etching, to selectively
statues of mythological figures, has in- In the majority of the cases, addi- remove the exposed material and form
spired enthusiasts to declare 3D printing tive manufacturing techniques such as three-dimensional shapes (Fig. 2). The
a significant contributor of the 4th in- selective laser sintering (SLS), stereo- laser beam, focused inside glass, locally
dustrial revolution, also called the Dig- lithography (SLA) or fused deposition modifies the refractive index of the mate-
itization Era. Direct manufacturing out modeling (FDM) are used, where one rial and creates patterns that can be used
of 3D printing is considered a promising layer at a time is created, each layer on to realize integrated optical components
source of potential economic impact in top of the previous until the final object or to develop, by chemical etching, even
industry for the upcoming years. Ac- is complete. The processes vary between three-dimensional structures, with high
material melting and subsequent depo- precision, aspect ratio and complexity.
sition, or through solidifying material Today, this technology platform is a stan-
Company using lasers. Although the technologies dardized process compliant to the ISO
are evolving rapidly, there are still lim- 13485:2016, and a micromachining ref-
FEMTOprint itations in building speed, limited ob- erence in the industrial manufacturing of
Muzzano, Switzerland ject size, precision and resolution, lim- micro-devices. Further to optical patterns
FEMTOprint SA is a Swiss high-tech company man- ited material strength and homogeneity, and 3D components, new complemen-
ufacturing 3D printed microdevices out of glass and incompatibility to high temperatures or tary capabilities include glass-to-glass en-
other transparent materials (e.g. fused silica and living tissues such as the human body, capsulation at low temperature, hole drill-
borosilicate) with sub-micron resolution, enabling
and in some cases the need for mechan- ing, glass cutting, and a self-developed
the integration of fluidic, optical and mechanical
functionalities in single monoliths at nano- and ical support structures and a post-pro- thermal polishing process to reduce the
micro-scale. Through the innovative FEMTOPRINT cessing step for residual removing and surface roughness below 10 nm Ra.
tech-platform, Prism Award Finalist (2015) and ISO smoothen surface. The advantages of the technique
13485:2016 certified, the company is transforming At the micro scale, a more pre- consent the reduction of manufacturing
the way industrial, highly complex microsystems are cise technique, namely the subtrac- steps, tools and costs. The direct writing
conceived.
tive manufacturing, has gained sig- process works in an out-of-cleanroom
www.femtoprint.ch nificant success where high precision, environment. It does not need masks,
complexity and resolution are critical post-processing to remove residuals and
32 Laser Technik Journal 1/2018 © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Additive Manufacturing
Healthy retina Retinal vein occlusion
Laser exposure Chemical etching
Fig. 3 Com-
Ø 20 µm parison of ret-
inal veins and
vision effect
of healthy
retina and
1.0 mm RVO (Source:
Instant Lab,
Galatea Lab /
Fig. 2 Schematic view of the FEMTOPRINT process Web)
is a versatile solution for rapid proto- quality. Thanks to the unique 3D capa- RVO can be treated by cannulation
typing and serial productions, reducing bilities, innovative and cost-effective and injection of therapeutic agents in
new product development cycles. The medical tools, implants and diagnostic the affected vein to remove clots, which
novel technology is giving the oppor- chips can be easily fabricated. are limiting the oxygen transportation
tunity to engineers to explore the third FEMTOprint, in collaboration with into the retina (Fig. 4). However, can-
dimension at microscale with sub-mi- Galatea Lab, Instant Lab (EPFL, Swit- nulation of small retinal veins is con-
cron resolution, adding feature-sized zerland), and the Jules-Gonin ophthal- sidered very risky and challenging, due
complexity and integrate optical, me- mic hospital (Lausanne, Switzerland), to multiple reasons. The fragility of the
chanical, fluidic and even electrical recently joined their forces into a con- puncturing tissues, the required punc-
functionalities to the device, resulting sortium to realize a challenging, glass- ture force (~20 mN) that is well below
in increased performances and reliabil- based compliant puncture tool for ret- human sensing capability, surgeon hand
ity in a miniaturized space. The critical inal vein occlusion (RVO), a common tremor, eye motion during surgery and
alignment of 2D microcomponents and retinal vascular disorder causing severe the dimensions of the tool that need to
the time-consuming assembly steps are loss of vision and affecting around 16 be compatible with the vein [2]. Cur-
now overtaken issues. Adding even more million patients worldwide over fifty rent medical treatments do not address
creativity and complexity, devices made years old (Fig. 3). the underlying cause of vein occlusion
with this technology can be coupled with
complementary fabrications like metal
evaporation to create embedded elec-
trodes, several functionalization to form
hydrophobic or hydrophilic surfaces, or
coupling waveguides to structure opto-
fluidic devices. drug injection
Glass has a widespread technological
usage and is the main starting material
clot
of the process. At microscale, from an
ordinary, amorphous material, it takes
on surprising properties – including,
but not limited to, optical transpar- punctured vein
ency, thermal and chemical stability,
Fig. 4 Schematic view of a retinal vein cannulation (Source: A. Gijbels, KU Leuven)
low thermal expansion, high elastic-
ity (as it is known from optical fibers),
actuation stage spring
biocompatibility, homogeneity and un-
usual dielectric properties – that offers 3D pivots
a powerful combination for new types
of med-tech tools, biomedical chips
with antibacterial surface treatments,
micro-nozzles for nebulizers, integrated needle
optical devices and interconnects, to tuning stage
end up in micromechanical watch com- beam
ponents with embedded microfluidic
channels and shock absorber.
In the med-tech industry, the capa-
bilities of the technology significantly 1.0 mm
contribute to the improvement of med-
ical engineering and, therefore, of life Fig. 5 SEM image of the puncture tool (Source: Instant Lab and Galatea Lab)
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Laser Technik Journal 1/2018 33
www.photonicsviews.com
Energy
unstable tool is suitable also for long injection
Force
time. In an experimental trial, the tool
successfully cannulated pig eye retinal
∆E veins (Fig. 8). In its final configuration,
the surgical tool can be used in either
stand-alone mode or mounted onto a
Position robotic system.
The results of this challenging proj-
stable
ect demonstrated once more the capa-
Position Threshold force bility to boost engineering creativity
and design real three dimensional free
Fig. 6 Strain energy reaction force of a bistable mechanism (Source: Instant Lab and forms, taking advantage of material
Galatea Lab) properties to obtain medical applica-
tions at sub-micron resolution, with
30 600
measurement measurement high accuracy and complexity, accord-
simulation simulation
Forward switching force [mN]
25 500 ing to the ISO 13485:2016 medical de-
20 cannulation cannulation vice certification and industrial stan-
Stroke [µm]
400
15
stroke stroke dards for large volumes throughput.
300
10 Acknowledgements
200
5 This work is funded by the Swiss com-
0 100 mission for technology and innova-
0 5 10 15 20 25 30 0 5 10 15 20 25 30 tion, CTI. We thank all parties involved
Tuning [µm] Tuning [µm]
from the Jules-Gonin hospital, Galatea
Fig. 7 Experimental and numerical values of puncturing force and stroke for different tun- Lab and Instant Lab for the support, as
ing displacements (Source: Instant Lab) well as Mr. Mohamed Zanaty and Mr.
Thomas Fussinger for their contribu-
but only treat the complications such as fabricated out of a fused silica monolith tions to this work.
macular edema. that integrates three major features: DOI: 10.1002/latj.201800003
The developing group conceived, mechanical 3D cross pivots acting as a
[1] J. Manyika et al.: Disruptive technologies:
manufactured and tested a passive com- bistable mechanisms (i.e., having two
Advances that will transform life, business,
pliant tool for retinal vein cannulation stable states and one unstable state), flu- and the global economy (2013) p. 111
(RVC) that relies on a buckling mechan- idic channels in the needle tip to vehic- [2] M. Zanaty et al.: Safe Puncture Tool for Ret-
ical principle to safely and precisely can- ulate drugs and finally, optical elements inal Vein Cannulation (2017)
nulate veins in eye surgery, independent to measure applied forces (Fig. 5). [3] S. Henein: PhD thesis no 2194, EPFL
(2000).
of the actuation input. This has been The bistable mechanism releases
possible by combining the advanced a constant amount of energy when it
manufacturing capabilities of the passes from its unstable state to a stable
FEMTOPRINT technology with the state [3]. It follows that a threshold force
glass properties, like robustness and fa- can be obtained by limiting the stroke Author
vorable elasticity, transparency and bio- of the mechanism (Fig. 6). This ensures
compatibility. The element was entirely safe and precise cannulation of the reti- Alexander Steimle
nal vein, assuming a very thin wall, with holds a degree in busi-
ness administration
puncturing force lower than the thresh-
with a major in busi-
old force, cannulation is guaranteed. ness development of
The surgeon simply displaces the mech- the Haute École de
anism across its unstable state. Gestion in Lausanne,
Experiments conducted to-date have Switzerland. He has
been very promising. The stability pro- been working in tech-
nology and med-tech
gramming of the double pinned bistable start-ups in Europe and Brazil, as an entre-
beam gives control over puncture force preneur and from the VC perspective, where
and stroke. The puncturing method has he led the advisory business (Criatec Fund
then been validated by FEM simulations and Venerdì Investments). Back in Switzer-
and experimental measurements (Fig. 7), land in January 2016, he joined FEMTOprint
as a Business Developer and is currently
demonstrating several advantages for
Head of Sales and responsible for Med-tech
both the patient and the surgeon: Punc- application developments.
turing the force is independent of the
surgeon force, actuation displacement Alexander Steimle, FEMTOprint SA, Via
Fig. 8 Measurement setup of the experiment on a pig eye is decoupled from puncturing position, Industria 3, CH-6933 Muzzano, Switzerland,
(Source: Instant Lab and Galatea Lab) it’s insensitive to hand tremor and the Email: alexander.steimle@femtoprint.ch
34 Laser Technik Journal 1/2018 © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimYou can also read
