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Surface++: A Scalable and Self-sustainable Wireless Sound Sensing Surface

Conference Paper

Surface++: A Scalable and Self-sustainable Wireless Sound Sensing Surface

Abstract and Figures

We present Surface++, which leverages our previous work SATURN, a self-powered flexible acoustic sensor, and ZEUSSS, a passive wireless sound communication technique using analog backscatter, to create a scalable and self-sustainable wireless sound sensing surface. Our new prototype allows for large area acoustic sensing using modular fabrication techniques with the promise of being fully printable. A single small Surface++ patch can be used to extend voice and gesture input for everyday surfaces, while our more sensitive Surface++ modular array allows for large-area context sensing and localization.
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Poster– Surface++: A Scalable and Self-sustainable Wireless
Sound Sensing Surface
Nivedita Arora1, Qiuyue Xue1, Dhruva Bansal1, Peter McAughan1, Ryan Bahr1, Diego Osorio1,
Xiaomeng Ma1, Alanson P. Sample2, Thad E. Starner1, Gregory D. Abowd1
1Georgia Institute of Technology, USA , 2University of Michigan, USA
Figure 1: Applications include (a) Interaction and control: adding Surface++ to objects and surfaces increases smart home as-
sistants’ listening range (b) Wearable control: attaching Surface++ to a shirt or jacket allows control using voice or tap gestures
(c) Context sensing and surveillance: a Surface++ array extends the acoustic sensing range to almost 10 meters allowing the
detection of coughing, laughing, talking, or a baby crying in a large-room setting (d) Outdoor localization: outdoor Surface++
patches can sense and communicate gunshot sounds to indoor transceivers for real-time triangulation of ring locations
ABSTRACT
We present Surface++, which leverages our previous work SAT-
URN [
2
], a self-powered exible acoustic sensor, and ZEUSSS [
1
],
a passive wireless sound communication technique using analog
backscatter, to create a scalable and self-sustainable wireless sound
sensing surface. Our new prototype allows for large area acoustic
sensing using modular fabrication techniques with the promise
of being fully printable. A single small Surface++ patch can be
used to extend voice and gesture input for everyday surfaces, while
our more sensitive Surface++ modular array allows for large-area
context sensing and localization.
CCS CONCEPTS
Human-centered computing Interaction devices
;
Hard-
ware Power and energy
;
Communication hardware, inter-
faces and storage.
KEYWORDS
Self-sustainable; Sensing; Vibration; Sound; Triboelectric Nano-
generator; Flexible electronics, Backscatter Communication; Low-
power; Acoustic Localization; Interaction and control
ACM Reference Format:
Nivedita Arora, Qiuyue Xue, Dhruva Bansal, Peter McAughan, Ryan Bahr,
Diego Osorio, Xiaomeng Ma, Alanson P. Sample, Thad E. Starner, Gregory
D. Abowd. 2019. Poster: Surface++: A Scalable and Self-sustainable Wireless
Permission to make digital or hard copies of part or all of this work for personal or
classroom use is granted without fee provided that copies are not made or distributed
for prot or commercial advantage and that copies bear this notice and the full citation
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For all other uses, contact the owner/author(s).
MobiSys ’19, June 17–21, 2019, Seoul, Republic of Korea
©2019 Copyright held by the owner/author(s).
ACM ISBN 978-1-4503-6661-8/19/06.
https://doi.org/10.1145/3307334.3328615
Sound Sensing Surface. In The 17th Annual International Conference on
Mobile Systems, Applications, and Services (MobiSys
'
19), June 17–21, 2019,
Seoul, Republic of Korea. ACM, New York, NY, USA, 2 pages. DOI: https:
//doi.org/10.1145/3307334.3328615
1 INTRODUCTION
Power has long been a major design constraint for both mobile and
ubiquitous sensing applications. Ideally, sensing nodes would work
without the need of a wired or replaceable power source. In addi-
tion, they would be thin and exible so that they might conform
to the objects on which they are placed. We recently showed the
promise of such a self-sustaining acoustic sensor named SATURN
[
2
], and demonstrated its ability to leverage analog RF backscatter
to transmit the acoustic signal passively o the sensor [
1
]. With
Surface++, we explore how the performance of the SATURN sensor
can be improved to harvest more energy and/or increase its per-
formance as an acoustic sensor. This optimization enables a wide
variety of vibration and acoustic sensing applications. In addition,
we optimize our design making the system modular and printable.
2 SYSTEM ARCHITECTURE
The system architecture consists of two parts—a single or array of
self-sustainable acoustic sensors connected in series and a passive
communication component, which are explained below.
SATURN [
2
] (Figure 2a)
1
uses a Triboelectric Nanogenerator
(TENG) [
5
,
6
] to convert tiny vibrations induced on its surface into
an electric signal (Figure 2b). Electrically, SATURN can be con-
sidered as a variable capacitor and voltage source. Since voltages
sources in series add, we connected multiple SATURN patches to
form a SATURN array structure (Figure 2c). Each SATURN patch
in this array includes a half-wave rectier (Figure 2d), resulting in
1SATURN video: www.youtube.com/watch?v=OLuZHpa_FIM
Poster Session
MobiSys ’19, June 17–21, 2019, Seoul, Korea
543
constructive addition of voltage generated from each patch. Con-
structing a 3x3 array improves acoustic sensitivity and is able to
detect sound sources which are almost 6 meters away, a 3X im-
provement in range from a single patch backscatter. This modular
design is scalable in performance with additional SATURN patches
connected in series.
Figure 2: Self-sustainable acoustic sensing (a) SATURN : a
thin and exible self-powered microphone [2] (b) Triboelec-
tric Nanogeneration (TENG) (c) Array of SATURN patches
connected together in series with (d) half-wave rectiers to
sum sound signal response
We add passive communication using analog RF backscatter. Our
experimental apparatus (Figure 3a) consists of the Surface++ tag
and a transmitter-receiver pair operating in the UHF (900 MHz)
frequency band. The Surface++ tag consists of a SATURN array and
a dipole antenna connected in two dierent designs, both of which
allow for change in impedance when sound is present. The rst
design (Figure 3b), exploits SATURN as a variable voltage source
connected to a JFET, a voltage controlled impedance device to ef-
fectively cause impedance change in the tag. The second design
(Figure 3c), leverages SATURN itself as a variable capacitor which
causes impedance change due to change in reactance of the tag.
According to backscatter theory [
3
], this change in tag impedance
causes change in the reection coecient of the tag which eec-
tively amplitude modulates the carrier wave signal, such that the
back-scattered signal would include the audio signal information,
which can be extracted at the receiver end with simple signal pro-
cessing techniques. Both the designs are impedance matched with
the antenna to allow maximum modulation on backscatter signal.
The components in the second design specically can be printed.
3 APPLICATIONS AND DISCUSSION
The self-sustainablity and thin form factor of Surface++ allows it
to be added to everyday objects and surfaces. Figure 1 illustrates
Figure 3: System Architecture: (a) Backscatter apparatus in-
cluding Surface++ tag and transceiver (b) Surface++ tag de-
sign exploiting SATURN as variable voltage source (c) Sur-
face++ tag design exploiting SATURN as variable capacitor
possible applications of Surface++; the applications in 1a and 1c
have been demonstrated in working systems. Future research will
optimize performance for dierent sound frequencies as well as for
dierent backscatter radio carriers. Creating a fully printable and
cheaply reproducible Surface++ is a priority as it enables dierent
applications. For example, a wide deployment of sensors will enable
a demonstration of large scale audio localization for gunshot detec-
tion. Surface++ could also be used for acoustic failure monitoring
and diagnostics of large scale equipment in areas that are dicult or
dangerous to access, such as the turbines in a nuclear power plant.
Another technical priority is an analysis of the privacy implications
of Surface++ to determine how challenges such as providing notice,
choice and consent, and a sense of proximity and locality of the
eective range of the device might aect the design [4].
REFERENCES
[1]
Nivedita Arora and Gregory D Abowd. 2018. ZEUSSS: Zero Energy Ubiqui-
tous Sound Sensing Surface Leveraging Triboelectric Nanogenerator and Analog
Backscatter Communication. In The 31st Annual ACM Symposium on User Interface
Software and Technology Adjunct Proceedings. ACM, 81–83.
[2]
Nivedita Arora, Steven L. Zhang, Fereshteh Shahmiri, Diego Osorio, Yi-Cheng
Wang, Mohit Gupta, Zhengjun Wang, Thad Starner, Zhong Lin Wang, and Gre-
gory D. Abowd. 2018. SATURN: A thin and exible self-powered microphone
leveraging triboelectric nanogenerator. Proceedings of the ACM on Interactive,
Mobile, Wearable and Ubiquitous Technologies 2 (2018), 27.
[3]
RC Hansen. 1989. Relationships between antennas as scatterers and as radiators.
Proc. IEEE 77, 5 (1989), 659–662.
[4]
Marc Langheinrich. 2001. Privacy by design-principles of privacy-aware ubiquitous
systems. In International conference on Ubiquitous Computing. Springer, 273–291.
[5]
Zhong Lin Wang. 2015. Triboelectric nanogenerators as new energy technol-
ogy and self-powered sensors–Principles, problems and perspectives. Faraday
discussions 176 (2015), 447–458.
[6]
Zhong Lin Wang and Aurelia Chi Wang. 2018. Triboelectric Nanogenerator for
Self-Powered Flexible Electronics and Internet of Things. In Meeting Abstracts.
The Electrochemical Society, 1533–1533.
Poster Session
MobiSys ’19, June 17–21, 2019, Seoul, Korea
544
Article
Full-text available
We envision a new generation of computation devices, computational materials, which are self-sustainable, cheaply manufactured at scale and exhibit form factors that are easily incorporated into everyday environments. These materials can enable ordinary objects such as walls, carpet, furniture, jewelry, and cups to do computational things without looking like today's computational devices. Self-powered Audio Triboelectric Ultra-thin Rollable Nanogenerator (SATURN) is an early example of a computational material that can sense vibration, such as sound. SATURN can be manufactured from inexpensive components, is flexible so that it can be integrated into many different surfaces, and powers itself through the sound or vibration it is sensing. Using radio backscatter, we demonstrate that SATURN's sensed data is passively transmitted to remote computers, alleviating the need for batteries or any wired power for the material itself. The proliferation of these types of computational materials ushers an era of Internet of Materials, further blurring the distinction between the physical and digital worlds.
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We demonstrate the design, fabrication, evaluation, and use of a self-powered microphone that is thin, flexible, and easily manufactured. Our technology is referred to as a Self-powered Audio Triboelectric Ultra-thin Rollable Nanogenerator (SATURN) microphone. This acoustic sensor takes advantage of the triboelectric nanogenerator (TENG) to transform vibrations into an electric signal without applying an external power source. The sound quality of the SATURN mic, in terms of acoustic sensitivity, frequency response, and directivity, is affected by a set of design parameters that we explore based on both theoretical simulation and empirical evaluation. The major advantage of this audio material sensor is that it can be manufactured simply and deployed easily to convert every-day objects and physical surfaces into microphones which can sense audio. We explore the space of potential applications for such a material as part of a self-sustainable interactive system. Video : https://www.youtube.com/watch?v=OLuZHpa_FIM
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Triboelectric Nanogenerator for Self-Powered Flexible Electronics and Internet of Things
  • Lin Zhong
  • Aurelia Chi Wang
  • Wang
Zhong Lin Wang and Aurelia Chi Wang. 2018. Triboelectric Nanogenerator for Self-Powered Flexible Electronics and Internet of Things. In Meeting Abstracts. The Electrochemical Society, 1533-1533.