Sensors & Actuators
20 matches found.


A wearable paper based perspiration monitoring platform with passive and active visual indicators

paper, microfluidics, sensor, laser treatment

Hydration in humans is a delicate parameter. Even small deviations such as 2 percent from normal levels can affect a person’s cognitive and physical performance by more than 30 percent.Conventional methods for monitoring hydration are either invasive, require non-portable equipment or do not yield results immediately. Feedback from many experts including marathon directors, the Ironman World Championship, Olympic triathlon athletes and many collegiate and professional coaches, athletes, race directors and EMTs, followed by intensive product development in the lab has resulted in the prototype of a palm-size patch consists of filter paper that is laser-machined to create a radial array of strips, which are laminated with a water-impermeable film to form micro-channels. The channels are loaded with a water-activated dye at one end. As sweat secretion increases, the strips are activated sequentially, changing from blue to red and providing easily identifiable levels of moisture loss.

Publications

Low cost radiation dosimeter utilizing organic materials

Radiation, dosimeter, and microorganism (yeast)

Living matter undergoes physical (sometimes lethal) damage to their DNA when exposed to the ionizing radiation. If such physiochemical alterations to the DNA can be utilized to measure the absorbed dosage, it can provide an invaluable information regarding the biological damage to the organism. One particular organism that can serve such purpose (radiation surrogate) is the yeast, a eukaryotic microorganism with wide and ancient commercial applications in food and beverage industry. Yeast is a well-studied microorganism having homologous genetic sequence to humans. Based on this noble idea, the low-cost, wearable, film-type radiation sensor is developed that utilizes yeast as the sensing material, hence, producing an output that can be directly correlated to the DNA damage and cellular inactivation/death. Our impedance-based sensor output is a function of fermentation byproducts (i.e., generated CO2 and resulting dissolved carbonic acid) of the surviving yeast (S. cerevisiae) after exposure to the ionizing radiation. A prototype sensor with dimensions of 18×18mm2 shows a maximum sensitivity of 0.154 Ω/Ω0decade-rad.

Publications

A Paper-Based Oxygen Generation and Sensing Platform

Bioflex - Chronic wound management - Parchment paper - Hydrogen peroxide - Manganese dioxide

A flexible, parchment paper/PDMS based platform for local wound oxygenation is fabricated and characterized. The platform consists of a PDMS microfluidic network bonded to a parchment paper substrate. Generation of oxygen occurs by flowing H2O2 through the channels and chemically decomposing it via a catalyst embedded in laser-defined regions of the parchment paper. PDMS is bonded to parchment paper using partially cured PDMS followed by a brief air plasma treatment, resulting in a strong bond. For pressures below 110 Torr the parchment paper is observed to be impermeable to water and hydrogen peroxide. The oxygen permeability of parchment paper is measured to be 1.42 μL/(Torr mm2 min). Using a peroxide flow rate of 250 μL/min, oxygen generation in the catalyst spots raises the oxygen level on the opposite side of the parchment paper from atmospheric levels (21%) to 25.6%, with a long-term (30 h) generation rate of 0.1 μL O2/min/mm2. This rate is comparable to clinically proven levels for adequate healing. Device and material in vitro biocompatibility is confirmed with NIH 3T3 fibroblast cells via alamar blue assays.

Publications

Ultrasound-powered electrolytic pump for remote-controlled drug delivery

Ultrasound powering - micropump - electrolysis = drug delivery

Piezoelectric receiver feeds AC signal to a full-wave rectifying circuit to create a constant DC voltage for electrolysis.
The electrolytically-generated gas pressure will be accumulated for pumping the drug out.
Flow rate of 0.1 μL/s with a backpressure of 24.2 Torr.

Publications

Smart Diaper

Autonomous (urine-activated) wireless diaper-embedded UTI (Urinary Tract Infection) monitoring platform

Keywords: UTI nitrite sensor autonomous

The invented diaper-embedded system is comprised of a flexible urine-activated paper battery, a colorimetric detection unit (LED/strip/photodiode), associated circuitry, wireless transmitter, and metallic traces integrated on a hydrophobic flexible substrate. It provides a fully autonomous (stays dormant before urination) and wireless monitoring of UTI upon the urination, which does not require any operation/intervention from the patient/caregiver. The entire detection and data transmission process completes within 30 minute from the beginning of the urination.

Project website Publications