TY  - JOUR
A1  - Qiu, Xunlin
A1  - Benjamin, Aravindan Joseph
A1  - Raman Venkatesan, Thulasinath
A1  - Schmidt, Georg C.
A1  - Soler, Ricardo Alonso Quintana
A1  - Panicker, Pramul Muraleedhara
A1  - Gerhard, Reimund
A1  - Hübler, Arved Carl
T1  - Dielectric and electroacoustic assessment of screen-printed piezoelectric polymer layers as flexible transducers
BT  - influence of the electrode material
JF  - IEEE transactions on dielectrics and electrical insulation
N2  - Here, piezoelectric transducers consisting of a P(VDF-TrFE) layer with either silver or PEDOT:PSS screen-printed electrodes are studied. The influence of electrodes on the dielectric and electroacoustic properties are studied in dielectric-spectroscopy and ferroelectric-hysteresis measurements. Only when both the bottom and the top electrodes are made of silver, the typical dielectric relaxation of the P(VDF-TrFE) layer is clearly observed. When one or two of the electrodes are of PEDOT:PSS, a Debye-like relaxation is present. Compared with silver electrodes, PEDOT:PSS electrodes allow for moderate self-healing. Consequently, samples with bottom and top PEDOT:PSS electrodes can be poled to saturation, while samples with silver electrodes can hardly be poled to saturation due to destructive electric breakdown. Acoustic transducer measurements show that silver electrodes facilitate higher and broader frequency operation, while PEDOT:PSS electrodes bring slightly lower total harmonic distortion. Overall, the acoustic performance shows no significant deviations between differently electroded samples so that silver electrodes do not offer any advantages for the transducers studied here due to their much higher tendency for destructive electric breakdown.
KW  - poly(vinylidenefluoride-trifluoroethylene) P(VDF-TrFE)
KW  - dielectric
KW  - spectroscopy
KW  - ferroelectricity and piezoelectricity in polymers
KW  - screen
KW  - printing
KW  - printed electroacoustic thin-film transducers
Y1  - 2020
U6  - https://doi.org/10.1109/TDEI.2020.008864
SN  - 1070-9878
SN  - 1558-4135
SN  - 0018-9367
VL  - 27
IS  - 5
SP  - 1683
EP  - 1690
PB  - Institute of Electrical and Electronics Engineers
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Schneider, Matthias
A1  - Fritzsche, Nora
A1  - Puciul-Malinowska, Agnieszka
A1  - Baliś, Andrzej
A1  - Mostafa, Amr
A1  - Bald, Ilko
A1  - Zapotoczny, Szczepan
A1  - Taubert, Andreas
T1  - Surface etching of 3D printed poly(lactic acid) with NaOH
BT  - a systematic approach
JF  - Polymers
N2  - The article describes a systematic investigation of the effects of an aqueous NaOH treatment of 3D printed poly(lactic acid) (PLA) scaffolds for surface activation. The PLA surface undergoes several morphology changes and after an initial surface roughening, the surface becomes smoother again before the material dissolves. Erosion rates and surface morphologies can be controlled by the treatment. At the same time, the bulk mechanical properties of the treated materials remain unaltered. This indicates that NaOH treatment of 3D printed PLA scaffolds is a simple, yet viable strategy for surface activation without compromising the mechanical stability of PLA scaffolds.
KW  - surface modification
KW  - sodium hydroxide etching
KW  - poly(lactic acid)
KW  - 3D
KW  - printing
KW  - roughness
KW  - wettability
KW  - erosion
Y1  - 2020
U6  - https://doi.org/10.3390/polym12081711
SN  - 2073-4360
VL  - 12
IS  - 8
PB  - MDPI
CY  - Basel
ER  -