The closed-loop HMI system could compliantly interface with human body for teleoperating various robotics with haptic feedback.

Sustainable agricultural practices are vital to meet the needs of a rapidly growing global demand for food. Monitoring plant health is crucial for enhancing crop yields. Salicylic acid (SA) is a plant hormone that plays a key role in the defense mechanisms plants employ against various stress factors. Changes in SA levels serve as an indicator that a plant is experiencing stress. Here, we present a low-cost electrochemical sensor fabricated using porous laser-induced graphene material for the measurement of plant stress. It employs square wave voltammetry to monitor SA levels using a wireless potentiostat. The sensor shows a high sensitivity of 144.28 μA mM⁻¹ to SA, with a linear detection range of 6.6 μM to 200 μM and a limit of detection of 1.44 μM. The surface of the working electrode was modified with Nafion to enable continuous in situ stress monitoring. The sensor's practicality has been demonstrated through real-time stress monitoring in aloe vera and philodendron hederaceum plant species.

The COVID-19 pandemic revealed a pressing need for the development of sensitive and low-cost point-of-care sensors for disease diagnosis. The current standard of care for COVID-19 is quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). This method is sensitive, but takes time, effort, and requires specialized equipment and reagents to be performed correctly. This make it unsuitable for widespread, rapid testing and causes poor individual and policy decision-making. Rapid antigen tests (RATs) are a widely used alternative that provide results quickly but have low sensitivity and are prone to false negatives, particularly in cases with lower viral burden. Electrochemical sensors have shown much promise in filling this technology gap, and impedance spectroscopy specifically has exciting potential in rapid screening of COVID-19. Due to the data-rich nature of impedance measurements performed at different frequencies, this method lends itself to machine-leaning (ML) algorithms for further data processing. This review summarizes the current state of impedance spectroscopy-based point-of-care sensors for the detection of the SARS-CoV-2 virus. This article also suggests future directions to address the technology’s current limitations to move forward in this current pandemic and prepare for future outbreaks.

A Non-rigid Air Flow Active Sensor (NAFAS) to detect the respiratory patterns is introduced in this paper. The main part of NAFAS is an ionic electroactive polymer-based (i-EAP) soft sensor. It can accurately detect breathing patterns and has promising features to develop low cost, wearable, and ubiquitous spirometers. Patients with respiratory diseases need to take pulmonary function tests consistently. Hence, it is time-consuming and expensive. To address these problems, NAFAS presents point-of-care testing (POCT) of the respiratory system’s function. The proposed i-EAP based sensor is a small strip of Ionic Polymer Metal Composite (IPMC) that has been fabricated using a Nafion membrane and two Pt electrodes. A test, including different breathing patterns, is designed and is performed by several male and female subjects. Results show that the NAFAS can detect delicate breathing patterns with various frequencies in an appropriate manner.

Saliva has emerged as a primary biofluid for non-invasive disease diagnostics. Saliva collection involves using kits where individuals stimulate saliva production via a chewing device like a straw, then deposit the saliva into a designated collection tube. This process may pose discomfort to patients due to the necessity of producing large volumes of saliva and transferring it to the collection vessel. This work has developed a saliva collection and analysis device where the patient operates it like a lollipop, stimulating saliva production. The lollipop-mimic device contains yarn-based microfluidic channels that sample saliva and transfer it to the sensing zone embedded in the stem of the device. We have embedded electrochemical sensors in the lollipop platform to measure vanillin levels in saliva. Vanillin is the most common food flavoring additive and is added to most desserts such as ice cream, cakes, and cookies. Overconsumption of vanillin can cause side effects such as muscle weakness, and damage to the liver, kidneys, stomach, and lungs. We detected vanillin using direct oxidation at a laser-induced graphene (LIG) electrode. We showed a dynamic range of 2.5 μM to 30 μM, covering the physiologically relevant concentration of vanillin in saliva. The lab-on-a-lollipop platform requires only 200 μL of saliva and less than 2 minutes to fill the channels and complete the measurement. This work introduces the first sensor-embedded lollipop-mimic saliva collection and measurement system.