Deformable printed circuit boards that enable metamorphic electronics

A method to produce single-layer deformable and stretchable printed circuit boards is reported and applied to enable the realization of metamorphic electronic products that can take on new three-dimensional (3D) shapes. The models contain arrays with packaged surface mount devices and bare dies that integrate light-emitting diodes (LEDs) and transistors within a rubber matrix. The test structures morph from planar to spherical to cone-like topologies. In one approach, the thickness of the stretchable printed circuit board is locally adjusted to control the morphological changes. In addition, a three-dimensionally-shaped chaperon is introduced to enable more abrupt topological changes. A comparative study of various designs of the metallization layer and stress-relieving reinforcing elements identified a highly stretchable and deformable design (up to 315% or six thousand 150% stretch and release cycles), which shields the interface between the hard and non-stretchable components from high levels of stress

Skin-to-skin contact after birth and the natural course of neurosteroid levels in healthy term newborns

ObjectiveTo determine the postnatal course of neurosteroid levels in relation to gender, mode of delivery and the extent of skin-to-skin (STS) contact during the first days of life in healthy term newborns.Study designProspective observational study of 39 neonates in which parents recorded total duration of STS in the first 2 days and nine neurosteroids (dehydroepiandrosterone-sulfate, progesterone, pregnenolone, pregnenolone-sulfate, allopregnanolone, isopregnanolone, epipregnanolone, pregnanolone and pregnanolone-sulfate) were assayed from blood samples at birth and at 1-2 days of age.ResultsAll nine neurosteroid levels declined significantly during the first 2 days of life. Gender did not significantly affect the change in neurosteroid levels. The decline in neurosteroid levels was generally more pronounced in vaginal deliveries, and there was a trend toward a larger decline with more exposure to STS.ConclusionOngoing studies may better characterize the role of neurosteroids and the influence of STS in more critically ill and premature neonates