Page 75 - ITU Journal Future and evolving technologies Volume 2 (2021), Issue 3 – Internet of Bio-Nano Things for health applications

ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 3

4. EXPERIMENTAL WORKS 4.2 Macroscale experiments

4.1 Microscale experiments An experimental setup was presented in [174] to model
the diffusive channel. In this setup, a spray of isopropyl
A micro luidic chip for detecting a Deoxyribonucleic acid
alcohol was used as a transmitter and a metal oxide sen‑
(DNA) molecule was proposed in [166]. This chip was
sor was used as a receiver that generates a voltage based
fabricated using multilayer soft lithography, which con‑
on the concentration of alcohol received over the air. The
sists of two layers of silicone rubber i.e., Polydimethyl‑
distance between the transmitter and the receiver was
siloxane (PDMS), a low layer with several micro‑wells,
considered from 2 to 5 meters and spraying duration was
and a control layer. Possibilities of nano‑resonators made
also varied from 50 milliseconds to 200 milliseconds un‑
of Graphene sheets and Carbon Nano‑Tubes (CNTs) for der different trials. Moreover, the response of the receiver
transportation and detection of molecules at very low
was averaged over these trials and the unknown coef i‑
concentration were explored in [167]. These materials
cients in the diffusion equation were found by minimiz‑
detect the shift in wave velocity (inside CNT) and resonant
ing the difference between the experimental observations
frequencies due to the presence of external molecules. and the theoretically expected response.
The motion of water molecules inside the CNT channel
was demonstrated in this work. Moreover, nano‑pumping A 2×2 MIMO‑MC system was developed in [175] and
action to initiate the molecule low was also shown. This [176], where two alcohol sprays and two chemical sensors
setup could be helpful for the design of transmitters in MC. were used at the transmitter and receiver, respectively.
In this work, a micro‑controller for transmission and two
micro‑controllers for decoding the text message was used.
Silicon‑Nano‑Wire (Si‑NW)‑based biomolecule detection Simulation results showed a data rate improvement of 1.7
was presented in [168]. In [168], a faster response of times with respect to the SISO system. Signal‑to‑inter link
Si‑NW than the Ion‑Sensitive Field Effect Transistor (IS‑ interference of 14.567 was calculated using the MIMO test
FET) was shown. Also, the sensitivity of the Si‑NW sen‑ bed when the transmitter and receiver were separated by
sor was revealed to be dependent upon the pH level of the 90 cm and antenna separation was 40 cm. Such commu‑
surroundings, the geometry of the sensor, and its doping nication systems could be useful for structural high speed
level. In [169], detection of femtograms of mercury‑ion health monitoring for smart cities and also for the trans‑
was proposed using Bovine Serum Albumin (BSA) pro‑ mission of signals to robots in a subterranean (i.e, under
tein conjugated ZnO nano‑sphere (BCZ). In this work, a the earth surface) region where implementing radio fre‑
quency communication is challenging.
logarithmic variation of conductance of BCZ was demon‑
strated with the concentration of mercury‑ions. Further,
An experimental setup was demonstrated in [177] in
the formation of a complex between BCZ and mercury was
which a peristaltic pump is used as a transmitter and a
con irmed through luorescence spectroscopy. Note that
pH sensor is employed at the receiver. The peristaltic
the proposed work in [169] has several biomedical appli‑
pump used acid to transmit bit‑0 and base to transmit
cations such as detection of diseases related to ingestion
bit‑1 over the channel which contains water in a silicon
of mercury and other heavy metals, which are toxic for a
human body. tube. In the case of an acidic signal, the receiver gener‑
ated positive voltage and for the base signal, the receiver
generated negative voltage. For detection, two different
A microscale modulator was proposed in [170], which techniques were proposed in which Support Vector Ma‑
converted an optical signal from a Light‑Emitting Diode chine (SVM) and RNN are used. The SVM‑based detection
(LED) to a chemical signal consisting of protons. The scheme uses a linear relationship between the input and
proposed system was similar to one considered in [171], the output. Also, a slope‑based detector was used which
+
where incident light on bacteria released the H ions. On measures the rate of change of pH within a symbol in‑
the other hand, a pH sensor was employed at the receiver. terval. It was shown that RNN 13 performs better among
For this system, channel estimation schemes based on other detectors for a short symbol duration. On the other
short‑duration pilot signals and long duration previously hand, slope‑based detection performed the worst. Hence,
detected data were proposed. Moreover, the optimal training based detectors are suitable for cases where the
channel model is not known.
maximum likelihood detector and suboptimal derivative‑
based detector were also derived. Simulation results
In [178], the authors used a test bed that was similar to
showed that the system can achieve a bit rate of 1 bit per
[174]. In this setup, isopropyl alcohol spray and metal
minute. A Graphene‑based micro‑resonator for individ‑
oxide sensor was used for transmission and reception,
ual molecule detection of DNA, dopamine, and nicotine
13
was proposed in [172]. An ingestible pill with the bidi‑ RNN was trained using the slope values and corresponding bit
patterns.
rectional wireless interface was proposed in [173] for in‑
body nucleic acid‑sensing. In this work, transmit and re‑
ceived powers of the order of micro‑watts was demon‑
strated. Also, a receiver mode sensitivity of −59 dBm
−3
with BER of 10 was shown at the speed of 1 megabits
per second (Mbps).
© International Telecommunication Union, 2021 63