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Developing scalable electrical stimulating platforms for cell and tissue engineering applications is limited by external power source dependency, wetting resistance, microscale size requirements, and suitable flexibility. Here, a versatile and scalable platform is developed to enable tunable electrical stimulation for biological applications by harnessing the giant magnetoelastic effect in soft systems, converting gentle air pressure (100-400 kPa) to yield a current of up to 10.5 mA and a voltage of 9.5 mV. The platform can be easily manufactured and scaled up for integration in multiwell magnetoelastic plates via 3D printing. The authors demonstrate that the electrical stimulation generated by this platform enhances the conversion of fibroblasts into neurons up to 2-fold (104%) and subsequent neuronal maturation up to 3-fold (251%). This easily configurable electrical stimulation device has broad applications in high throughput organ-on-a-chip systems, and paves the way for future development of neural engineering, including cellular therapy via implantable self-powered electrical stimulation devices.

Introduction Percutaneous patent ductus arteriosus (PDA) occlusion has become the preferred therapeutic option, which uses fluoroscopy as the guidance. To reduce the x-ray exposure, PDA occlusion using the Amplatzer Duct Occluder II (ADO II) under guidance of transthoracic echocardiography only was conducted. This single center study aims to access the safety and efficiency of this new strategy. Methods and Results From June 2013 to May 2015, 63 consecutive PDA patients underwent transthoracic echocardiography-guided PDA occlusion through the femoral artery. Outpatient follow-up was conducted at 1, 3, and 6 months, and yearly. Sixty-two patients successfully underwent echocardiography-guided percutaneous PDA occlusion. One patient was converted to minimally invasive transthoracic occlusion due to failure of delivery sheath passage through tortuous PDA. Mean procedure duration was 24.3 ± 7.0 minutes; ADO II diameter averaged 4.6 ± 0.9 mm; 8 cases showed traces of residual shunt immediately after operation which resolved after 24 hours; and mean hospital stay was 3.4 ± 0.5 days. There was no occluder migration, hemolysis, pericardial effusion, pulmonary branch or aortic stenosis at mean 13.5 ± 4.8 months follow-up. Conclusions This study demonstrated that percutaneous PDA occlusion can be successfully performed under guidance of transthoracic echocardiography only and appears safe and effective while avoiding radiation and contrast agent use.

An integrated optoelectronic device is demonstrated with a high–mobility conjugated oligoaniline field-effect transistor (FET) driving a poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene)vinylene (MEH-PPV) light-emitting diode (LED). The FET fabricated with oligoaniline (16-mer) thin film as the semiconductor layer exhibits ideal source current–drain-source voltage characteristics. Its performance is close to those of inorganic amorphous silicon FETs, with field-effect mobilities of 0.1–1.0 cm2/V s and on–off current ratio of 106. The FET-LED integrated device exhibits a current of 8 × 10−4 A with the maximum brightness on the order of 10 cd/m2 at gate voltage of −100 V and drain-source voltage of 60 V. Copyright © 2003 John Wiley & Sons, Ltd.