Stretchable, wireless health monitoring patches to evaluate heart rate, blood oximetry, UV exposure, and skin coloration.

Researchers report advances in materials and designs for skin-integrated devices capable of measuring acoustic signatures.

wileyonlinelibrary.comresorbable environmental monitors, disposable devices, hardware-secure digital memories, and other applications that are not well served by conventional technologies. [ 1 ] Such types of systems represent a subset of a broader class of a technology referred to as transient electronics. Early work [ 2 ] examined sequentially dissolvable electronics in which variations in the thicknesses and types of the constituent materials determine a time sequence for dissolution across the areas of integrated devices. An important recent advance [ 3 ] in this fi eld followed from the realization of on-demand, triggered dissolution via a remotely controlled microfl uidic system. In the present paper, we demonstrate that these platforms can be extended for use in multistaged transformations of functional behaviors in the transient electronics by means of programmed microfl uidic chemical etching at Electronic systems that enable programmable transformation of functional behaviors by remote control or by autonomous responses to user-defi ned circumstances create unusual engineering opportunities, where physical changes in the hardware induce desired changes in operation. This paper presents materials and device architectures for technologies of this type, in which localized microfl uidic chemical etching of targeted constituent components in the electronics occurs in a sequential, selective manner. Custom circuits that include reconfi gurable radio-powered thermal actuators with analog amplifi ers and square waveform generators illustrate the concepts.

Process intensification focuses largely on process and equipment design. Much less emphasis has been placed on operational changes to achieve cost savings and increased efficiency. This article introduces the concept of dynamic intensification, defined as changes to the dynamics, operating strategy and/or control of a process that lead to a substantially more efficient processing path. This idea is illustrated in the context of binary distillation. Output multiplicity properties are exploited to establish a new periodic operating mode based on switching between two auxiliary products, which, on a time‐average basis, is more energy efficient than steady‐state operation. An extensive case study is presented concerning the distillation of a propanol–acetic acid mixture, confirming the theoretical developments. In contrast to previous research (e.g., on cyclic distillation), the present concept has significant advantages as it relies on existing hardware and exploiting system nonlinearity, rather than using specialized equipment operated in a discontinuous fashion. © 2018 American Institute of Chemical Engineers AIChE J, 65: 1162–1172, 2019

This paper applies the concept of dynamic intensification (defined as changes to the dynamics, operation strategy, and/or control of a process that lead to a substantially more efficient processing path) to binary distillation columns. The resulting strategy consists of manufacturing a target product as a blend of two auxiliary products, both having lower energy demands than a reference value, which corresponds to producing the target product(s) in a column operating at steady state. A discussion of the appropriate control structures and switching strategies between the two auxiliary products is provided. An extensive case study concerning the separation of a methanol–1-propanol mixture was carried out, demonstrating that energy savings in the order of 1.4% are possible with no disruption in product quality or production rate.