required to produce physical objects
and how to make the process more
interactive with a tighter feedback
cycle. To solve these challenges,
HCI researchers need to reach out
and collaborate with researchers in
such diverse disciplines as computer
graphics, mechanical engineering,
material science, architecture,
robotics, and design. An exciting
journey is ahead!
1. Baudisch, P. and Mueller, S. Personal
fabrication. Foundations and Trends® in
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A technique for 3D printing of soft
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Conference on Human Factors in Computing
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3. Oxman, N. GLASS II. The Mediated
Matter Group. Milan Design Week, 2017.
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A., Pfisterer, L., Guimbretière, F., and
Baudisch, P. WirePrint: 3D printed
previews for fast prototyping. Proc. of
UIS T ’ 14, 273–280.
5. Mueller, S., Mohr, T., Guenther,
K., Frohnhofen, J., and Baudisch,
P. faBrickation: Fast 3D printing
of functional objects by integrating
construction kit building blocks. Proc. of
CHI ' 14, 3827–3834.
6. Willis, K. D.D., Xu, C., Wu, K.-J.,
Levin, G., and Gross, M. D. Interactive
fabrication: New interfaces for digital
fabrication. Proc. of TEI ’ 11, 69–72.
7. Weichel, C., Lau, M., Kim, D., Villar,
N., and Gellersen, H. W. MixFab: A
mixed-reality environment for personal
fabrication. Proc. of CHI ' 14, 3855–3864.
8. Teibrich, A., Mueller, S., Guimbretière, F.,
Kovacs, R., Neubert, S., and Baudisch, P.
Patching physical objects. Proc. of UIST
' 15, 83–91.
9. Mueller, S., Fritzsche, M., Kossmann, J.,
Schneider, M., Striebel, J., and Baudisch, P.
Scotty: Relocating physical objects across
distances using destructive scanning,
encryption, and 3D printing. Proc. of TEI
' 15, 233–240.
Stefanie Mueller is an assistant professor
at MI T CSAIL. In her research, she develops
novel interactive technologies that advance
personal fabrication. She regularly serves as
a program committee member for both ACM
CHI and ACM UIST, and was a general co-chair
for the 2017 ACM Symposium on Computational
Sustainability. With 3D printing
hardware becoming more and more
available, a future in which everyone
can produce physical objects is
getting closer. However, in contrast
to digital design, physical objects
require actual materials and produce
actual physical waste. Personal
fabrication is currently a one-way
process: Once an object has been
fabricated with a 3D printer, it cannot
be changed. Any alteration requires
printing a new version from scratch.
Instead of reprinting the entire
object, Patching Physical Objects
[ 8] proposes to change the existing
object (Figure 4): Users mount the
object into the 3D printer, then load
both the original and the modified
3D model into a piece of software,
which in turn calculates how to patch
the object. After identifying which
parts to remove and what to add, the
system locates the existing object in
the printer using the system’s built-in 3D scanner. After calibrating the
orientation, a mill first removes the
outdated geometry, and then a print
head prints the new geometry in place.
Intellectual property. Once an
object is available as a digital 3D
model, users can fabricate it on their
3D printers for only the cost of the
material, bypassing the cost that
normally compensates the designer
for his or her work. A recent survey
found that 80 percent of top 3D
designers don’t share their designs
for fear of theft. Thus, securing
intellectual property rights might
close the content gap that is currently
delaying further adoption of personal
Scotty [ 9] is an appliance that
allows users to send objects to distant
locations while maintaining copyright
(Figure 5). For the object transfer
not to interfere with intellectual
property—that is, to keep the object
unique and to not produce illegal
copies in the process—the object
needs to disappear at the sender
location and reappear at the receiver
location. Scotty achieves this by
( 1) destroying the original during
scanning by shaving off one layer at a
time with the built-in milling machine.
Each layer is captured with the built-in camera. ( 2) During transmission,
Scotty prevents “men-in-the-middle”
from fabricating a copy of the object
by encrypting the object using the
receiver’s public key. ( 3) Finally,
during refabrication, Scotty prevents
the receiver from making multiple
copies by maintaining an eternal log of
objects already fabricated.
WHAT IS DOWN THE ROAD?
On the technology side, we are
seeing rapid progress every year.
For instance, the 3D-printing
company 3D Systems stated that
3D printing speed on average has
doubled every 24 months over the
past 10 years. Similarly, we see new
3D-printing materials coming out
in short intervals. Material science
journals, such as Advanced Materials,
can provide HCI researchers with
insights on what is coming out soon.
Printing new functional materials
with properties such as light-activated shape changing will allow
for new types of sensors and actuators
that will enable completely new
interactive applications. On the other
hand, there are many open research
questions concerning the workflow
with 3D printers. They include how
to provide the necessary domain
knowledge and machine knowledge
DOI: 10.1145/3125399 COPYRIGHT HELD BY AUTHOR. PUBLICATION RIGH TS LICENSED TO ACM. $15.00
Figure 5. Scotty [ 9] allows the relocation of physical objects while preserving intellectual
property, i.e., keeping the object unique.