Electrophoretic drug delivery for seizure control

Journal: Science Advances

Authors: C. M. Proctor and G. G. Malliaras et al.

Affiliation: The University of Cambridge (UK)

Publication date: 2018.08.29

Summarized by Inyeol Yun

 

– Topics
v. Neural probes incorporation an ion pump for on-demand drug delivery and   electrodes for recording local neural activity. (Fig. 1)
v. Seizure-like events (SLE) were induced by local injection of 4-aminopryridine (4AP)
v. γ-aminobutryic acid (GABA) inhibit neural activity.

1.png

<Fig. 1>

–Fabrication
v. Gold electrode: ion pump source electrode, PEDOT:PSS electrode : recording   electrophysiological activity (Fig. 2)

2.png

<Fig. 2>

– Results
v. Ion transfer efficiency: ~10-3 nmol of GABA transported in few seconds (Fig. 3)

3

<Fig. 3>

  v. Seizure control (Fig. 4)

4.png

<Fig. 4>

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Low-Power, Electrochemically Tunable Graphene Synapses for Neuromorphic Computing

Journal: Advanced Materials

Authors: M. T. Sharbati and F. Xiong et al.

Affiliation: The University of Pittsburgh (USA)

Publication date: 2018.07.23

Summarized by Inyeol Yun

 

– Background
v. The neural network in a human brain has ≈1011 neurons. Each neuron is typically   connected to ≈5,000 to 10,000 other neurons through synapse.
v. Synapse plasticity is the ability of synapses to strengthen or weaken over time, in   response to increases or decreases in their activity (Wikipedia). It related to memory   function.
v. Typical artificial synapses cannot mimic the analog behaviors of biological synapses.
v. In this paper, authors demonstrate the synapse plasticity using “nano-battery”   technology. (Fig. 1)

1.png

<Fig. 1>

– Structure & Fabrication
v. Graphene layers – Solid electrolyte (LiClO4 in poly(ethylene oxide) (PEO) – Lithium   iron phosphate (LFP) (Fig. 2)

2.png

<Fig. 2>

 v. Metal contacts (80 nm of Cu) were defined by e-beam lithography and deposited   through e-beam evaporation.
v. Real image (Fig. 3)

3.png

<Fig. 3>

– Results
v. Raman spectroscopy shows weakening of bond between graphene layers as   increasing Li-ion. (Fig. 4)

4.png

<Fig. 4>

 v. Resistance change (Figure. 5)

5.png

<Fig. 5>

Flexible wireless powered drug delivery system for targeted administration on cerebral cortex

Journal: Nano Energy

Authors: S. Sung and K. Lee et al.

Affiliation: KAIST (Republic of Korea)

Publication date: 2018.06.07

Summarized by Inyeol Yun

 

– Flexible wireless powered drug delivery system (Fig. 1)

1.png

<Fig. 1>

– Device fabrication
v. Structure (Fig. 2)

2.png

<Fig. 2>

 v. Steps (Fig. 3)

3.jpg

<Fig. 3>

– Technical points
v. Heat transfer simulation (LLO damage x) (Fig.4)

4.png

<Fig. 4>

 v. Gold membrane dissolution process (Fig. 5)

5a

5

<Fig. 5>

  v. Wireless power efficiency (Fig. 6)

6.png

<Fig. 6>

Functional, RF-Trilayer Sensors for Tooth-Mounted, WirelessMonitoring of the Oral Cavity and Food Consumption

Journal: Advanced Materials

Authors: P. Tseng and F. G. Omenetto et al.

Affiliation: Tufts University (U.S.A.)

Publication date: 2018.03.23

Summarized by Inyeol Yun

 

– Structure
v. Au-Ti-(interlayer)-Ti-Au
v. 2 mm x 2 mm size

fig1.png

Fig. 1

fig2.png

Fig. 2

 

– Result
v. S11 change of various solvents and solutions (Fig. 3)
v. Resonant frequency vs. glucose concentration (Fig. 4)
v. Resonant frequency vs. temperature and pH (Fig. 5)

fig3.png

Fig. 3

fig4.png

Fig. 4

fig5

Fig. 5

 

– Measurement
v. In-vitro : HP 8753E impedance analyzer
v. In-vivo : miniVNA (Fig. 6)

fig6.png

Fig. 6

Gauging force by tapping tendons

Journal: Nature Communications

Authors: J. Martin and D. G. Thelen et al.

Affiliation: University of Wisconsin-Madison (USA)

Publication date: 2018.04.23

Summarized by Inyeol Yun

 

– Principle

v. tapping tendons à vibration velocity change such as guitar!!

fig1

Fig. 1

 

– Result
v. High load  High wave speed (Fig. 2)
v. Achilles wave speed vs. ankle torque (Fig. 3)
v. Wave speed vs. running speed (Fig. 4)

fig2.png

Fig. 2

fig3

Fig. 3

fig4.png

Fig. 4

Biodegradable Piezoelectric Force Sensor

Journal: Proceedings of the National Academy of Sciences

Author: Eli J. Curry and Thanh D. Nguyen et al.

Affiliation: University of Connecticut

Publication date: 2018.01.16

Summarized by Inyeol Yun

 

– Structure
v. PLA Encapsulator – Molybdenum – Piezo. PLLA – Molybdenum – PLA Encapsulator (Fig. 1)

fig1.png

Fig. 1

 

– Fabrication
v. Cut the Molybdenum and PLLA film.
v. The PLLA film was sandwiched between two Mo electrodes.
v. Encapsulator was sealed using a combination of the biodegradable PLLA glue and a thermal bag sealer for 4 seconds. (Fig. 2)

fig2.png

Fig. 2

 

– Principle
v. Piezoelectricity (Fig. 3)
v. PLLA : new piezoelectric material (normally not piezoelectric material) (Fig. 4)
v. PLLA -> shear stress -> nucleation -> piezoelectricity (Fig. 5)

fig3.png

Fig. 3

fig4.png

Fig. 4

fig5

Fig. 5

 

– Result
v. Vibration test: Drain ratio (DR) 2.5 output is largest but it is not conclusive optimal DR (Fig. 6)
v. Pressure – Voltage with charge amplifier circuit
v. Biocompatible, Biodegradable test (Fig. 7)
v. In-vivo test: inside the abdominal cavity of a mouse to monitor the pressure of diaphragmatic contraction (Fig. 8)

fig6.png

Fig. 6

fig7.png

Fig. 7

fig8.png

Fig. 8

Cephalopod-inspired Design of Electro-mechano-chemically Responsive Elastomers for On-demand Fluorescent Patterning

Journal: Nature Communications

Publication date: 2014.09.16

Summarized by Seongmin Park

 

– Squid Coloration Principle
v. Pigment-containing sac: Area controlled by radial muscle
v. Radial muscle: control colored area

fig1.png

Fig. 1

 

– EMCR elastomer
v. Fabrication of electro-mechano-chemically responsive (EMCR) elastomer – Figure 2
v. Applying force → fluorescent, applying visible light → transparent – Figure 3

fig2.png

Fig. 2

fig3.png

Fig. 3

 

– Applied strain vs. fluorescent intensity
v. Figure 4

fig4.png

Fig. 4

 

– Electrically controllable structure
v. Initial structure – Figure 5
v. With high electric field – Figure 6
v. Induced high strain – Figure 7

fig5.png

Fig. 5

fig6.png

Fig. 6

fig7.png

Fig. 7

 

– Wrinkle generation principle
v. Cratered structure is more stable than flat structure when it’s in high electric field – Figure 8, 9

fig8.png

Fig. 8

fig9

Fig. 9

 

– Electric field vs. color image
v. Figure 10

fig10.png

Fig. 10

fig11.png

Fig. 11