skip to main content


Search for: All records

Creators/Authors contains: "Escobar, Alberto Ranier"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Abstract

    Ion consumption plays key roles in maintaining bodily homeostasis and health. Here passive wireless, multimineral comonitoring arrays are studied that may potentially be utilized for emerging applications in precision nutrition. RF biosensors targeting select minerals (calcium or magnesium demonstrated herein) are built from integrating ion‐selective membranes within a broadside‐coupled split ring resonator architecture. RF sensors are typically monitored one at a time and such platforms often are incapable of comeasuring multiple confounding components. To address this challenge, this sensor arrays are further directly integrated alongside a conformal, custom readout coil that optimizes multi‐RF sensor readout. Such optimized networks exhibit enhanced signal clarity, further facilitating coextraction of multiple ion components. A simple method of extracting multimineral concentrations from food even despite the imperfect selectivity of divalent ion‐selective membranes is introduced. This passive wireless, zero‐electronic ion‐monitoring platform integrates seamlessly on foodware or packaging, possessing many applications in food measurement.

     
    more » « less
    Free, publicly-accessible full text available November 1, 2025
  2. Free, publicly-accessible full text available August 19, 2025
  3. Abstract

    The human body exhibits complex, spatially distributed chemo-electro-mechanical processes that must be properly captured for emerging applications in virtual/augmented reality, precision health, activity monitoring, bionics, and more. A key factor in enabling such applications involves the seamless integration of multipurpose wearable sensors across the human body in different environments, spanning from indoor settings to outdoor landscapes. Here, we report a versatile epidermal body area network ecosystem that enables wireless power and data transmission to and from battery-free wearable sensors with continuous functionality from dry to underwater settings. This is achieved through an artificial near field propagation across the chain of biocompatible, magneto-inductive metamaterials in the form of stretchable waterborne skin patches—these are fully compatible with pre-existing consumer electronics. Our approach offers uninterrupted, self-powered communication for human status monitoring in harsh environments where traditional wireless solutions (such as Bluetooth, Wi-Fi or cellular) are unable to communicate reliably.

     
    more » « less
  4. Abstract

    Passive and wireless Radio‐Frequency (RF) sensors are a unique, enabling modality for emerging applications in environmental sensing. These sensors exhibit several key features that may unlock new functionalities in complex environments: sensors are composed of zero electronic components, are wirelessly interrogated even in opaque media, and structures are often inherently biocompatible. Such capabilities make it unique in the realm of sensing architectures. Here, the broadside‐coupled, split‐ring resonator is studied as a compact and versatile model structure for RF sensing (of potentially mechanical and biochemical environments). A new analytical model is derived to assess resonator behavior—these yield a rapid, first‐order approximation of the resonator resonant frequency or sensitivity. Finally, experimental investigations into how sensors may be optimally designed, sized, and interrogated to enhance sensitivity or spectral intensity are performed. These studies encompass a wide variety of potential dimensional and dielectric modifications that may be relevant to emerging sensors. Last, hydrogel polymeric sensors are synthesized and studied to assess how practical sensors may deviate in response from expectations. Such investigations lay the groundwork for how such sensing architectures may be adapted to fit application needs.

     
    more » « less
  5. Abstract

    Nutrition measurement has broad applications in science, ranging from dietary assessment, to food monitoring, personalized health, and more. Despite its importance, there are currently no tools that offer continuous cotracking of nutrients direct from food. In this study, the multiscale engineering of silk biopolymer‐interlayer sensors is reported for comonitoring of nutrients. By manipulating various nano‐ to mesostructural properties of such biosensors, sensors are obtained with programmable sensitivity and selectivity to salts, sugars, and oils/fats. Notably, this approach requires no specialized nanomaterials or delicate biomolecules. Programmable biosensors are further formatted for wireless readout and characteristics of these passive, wireless nutrient monitors are studied in vitro. As a proof of concept, the discrimination and comonitoring of salt, sugar, and fat content direct from real, complex foods such as milk, meat, soup, and tea drinks are demonstrated. It is anticipated that such sensors can be utilized in emerging dietary tools for applications across food tracking and human health. In addition, such strategies are expected in structural engineering of sensors to be adaptable to existing or emerging selective or partially selective sensors.

     
    more » « less
  6. Abstract

    Manipulation of magnetic materials (including remote‐controlled motions or structural deformations) plays a major role in modern micro‐ to macro‐scale systems. Magnetic operations create highly predicable outcomes in the behavior of systems, however these have difficulty performing subordinate and/or higher‐order operations. This lack of selectivity remains a critical drawback of magnetic manipulation schemes. Here, a strategy of engineering highly selective magnetic responses is studied and implemented. This is achieved by combining magnetic barcodes (“keys” encoded with layers of magnetic anisotropy) with programmable magnetic platforms (locking select codes in place with matching spatiotemporal magnetic fields). Presently, barcodes are realized by encoding hydrogel with sequences of magnetic microchains with binary spatial orientations. A number of unique capabilities of this approach are studied, including the untethered, selective anchoring of magnetic barcodes to programmable sites, as well as the selective latching of barcodes against background magnetic tags during flow. This approach may be used as a building block in micro‐ to macro‐scale magnetic interfaces.

     
    more » « less