Monthly Archives: November 2017

Robust resistive memory devices using solution-processable metal-coodinated azo aromatics

Journal: NATURE MATERIALS

Publication date: 2017.10.23

Summarized by Taewon Seo

 

– Structure
v. Molecular view of compound mer-[Ru(L)3](PF6)2 structure (Fig. 1-a)
v. Schematic of device(Fig.1-b)
v. Basic device (type A), second device (type B) (Fig.1-c)
v. Au nanoparticles are sputtered in type B

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Fig. 1

 

– Characteristics
v. Current density-voltage characteristics for device A (Fig.2)
v. Current density-voltage characteristics for device B (Fig.2)
v. Nano scale test device(Fig.3)

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Fig. 2

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Fig. 3

 

– Mechanism
v. Raman spectra measured for thin-film devices (E1 = 1,365cm-1, E2 = 1,313cm-1, E3 = 1,275cm-1) (Fig.4)
v. E1 : neutral, E2 : single-electron reduction, E3 : doubly reduced species
v. Correlation between Raman peaks and film conductance (Fig.5)
v. In the on-state, all molecules are same redox state.

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Fig. 4

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Fig. 5

 

– Role of counterions
v. LUMO of [Ru(L)3]2+, the strongest π-acceptor ligands (Fig.6)
v. Variation in HOMO and LUMO energy levels (Fig.7)
v. Variation in Electrode and LUMO energy levels (Fig.8)
v. The spatial molecule and counterion results in the formation of dipoles.
v. The applied electric field in the device displace counterions from on pocket to another.

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Fig. 6

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Fig. 7

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Fig. 8

 

– Device performance
v. Read-write pulse sequence for device A & B

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Fig. 9

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Flexible Piezoelectric Devices for Gastrointestinal Motility Sensing

Journal: Nature Biomedical Engineering

Author: C. Dagdeviren and G. Traverso et al.

Affiliation: Massachusetts Institute of Technology, Cambridge, United States

Publication date: 2017.10

Summarized by Inyeol Yun

 

– Piezoelectric gastrointestinal motility sensor (Fig. 1)

v. 12 groups in series, 10 groups in parallel. (Fig. 2)

v. Sensing principle: piezoelectric material (Fig. 3)

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Fig. 1

Fig. 2

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Fig. 3

 

– Biocompatibility

v. Live/dead cytotoxicity analysis of HT-29-MTX-E12, HeLa and C2BBe1 cells incubated with neutralized simulated gastric fluid for three days.

v. Cells treated with 70% ethanol were used as a negative control.

v. Cells treated with neutralized gastric fluid that had not been in contact with the microchips were used as a positive control

v. Green indicates viable cells and red indicates dead cells. (Fig. 4)

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Fig. 4

 

– Result

v. Voltage output for a flouting and glued PZT GI-S in a balloon with 200 ml water infusion (Fig. 5)

v. In vivo evaluation in Yorkshire swine model (Fig. 6)

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Fig. 5

fig6.png

Fig. 6

 

– Reference

v. http://blog.naver.com/kt9411/150165849100 (2017-11-21)

The Dermal Abyss: Interfacing with the Skin by Tattooing Biosensors

Journal: International Symposium on Wearable Computers

Author: Katia Vega, Nan Jiang and Xin Liu et al.

Affiliation: MIT Media Lab, Harvard Medical School

Publication date: 2017.09.11

Summarized by Jinpyeo Jeung

 

– Health monitoring tattoos (Fig. 1)
v. Glucose, pH and Sodium sensor.
v. principle: Using biosensor ink for tattoos.

fig1.png

<Fig. 1>

 

– Biosensors (Fig.2)
v. Sodium biosensor: diaza-15-crown-5. Selectively bind to Na+ ions.
v. pH biosensor: anthocyanin.(Fig. 3)
v. Glucose biosensor: extracted from reagent strips.

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<Fig. 2>

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<Fig. 3>

 

– Result
v. Glucose biosensor without glucose and with glucose (Fig. 4)
v. pH biosensor at pH 8.0 and pH 7.0 (Fig. 5)
v. Sodium biosensor with 100mmol/L Na+ ions under visible light and UV light (Fig. 6)
v. designs made by a tattoo artist in ex vivo pig skin.(Fig.7)

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<Fig. 4>

fig5.png

<Fig. 5>

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<Fig. 6>

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<Fig. 7>

 

– Application by monitoring health status
v. Diabetes.
v. Dehydration.
v. pH Balance.

Wearable Ring-Based Sensing Platform for Detecting Chemical Threats

Journal: ACS SENSORS

Author: J. R. Sempionatto and Joseph Wang et al.

Affiliation: University of California, United States

Publication date: 2017.10.11

Summarized by Inyeol Yun

 

– Ring-based Chemical Sensor (Fig. 1)
v. Explosives (DNT, H2O2) and nerve agent (MPOx) sensor
v. Printing fabrication (Fig. 2)
v. Sensing principle: redox reaction between working electrode and chemical (Fig. 3)

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Fig. 1

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Fig. 2

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Fig. 3

 

– Materials
v. Working electrode: carbon ink (1), carbon-Prussian blue ink (2)
v. Reference, counter electrode: Ag/AgCl ink
v. All inks were purchased

 

– Result
v. Liquid-phase threat detection at the ring-based electrochemical system (Fig. 4)
v. Vapor-phase threat detection at the ring-based electrochemical system (Fig. 5)
v. Selectivity test (Fig. 6)

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Fig. 4

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Fig. 5

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Fig. 6