Stretchable, degradable semiconductors for health monitoring

Zhenan Bao has developed stretchable, degradable semiconductors, with the ability to conform to internal organ surfaces, and dissolve and disappear when no longer needed.

This is the first example of a material that simultaneously possesses the three qualities of semiconductivity, intrinsic stretchability and full degradability. Other attempts resulted in semiconductors that either did not break down completely, or had reduced electrical performance when stretched.

Zhenan Bao has solved this problem – by combining a rubbery organic polymer with a semiconducting one.

Her team synthesized and mixed the two degradable polymers, which self-assembled into semiconducting nanofibers embedded in an elastic matrix. Thin films made of these fibers could be stretched to twice their normal length without cracking or compromising electrical performance. When placed in a weak acid, the new material degraded completely within 10 days.   (Bao said that it would take much longer in the human body.) The semiconductor was  non-toxic to human cells growing on the material in a petri dish.


Zhenan Bao will discuss this technology, and more of her latest work, at Wearable Tech + Digital Health + Neurotech Silicon Valley on Feb 11-12

Sweat sensor monitors metabolites to detect gout, metabolic and other disorders

Caltech’s Wei Gao has developed a wearable sensor that monitors metabolites and nutrients in blood by analyzing sweat. Previously developed, less sensitive, sweat sensors mostly target electrolytes, glucose, and lactate.

Gao develops devices based on microfluidics, which minimize the influence of sweat evaporation and skin contamination on sensing accuracy.  Previous microfluidic-based wearable sensors were mostly fabricated with a lithography-evaporation process, requiring  complicated and expensive fabrication processes. Gao uses graphene.

In a study, the sensor was used to measure respiratory rate, heart rate, and levels of uric acid and tyrosine. Tyrosine can indicate metabolic disorders, liver disease, eating disorders, and neuropsychiatric conditions. Elevated Uric acid is associated with gout.

Gao believes that the high sensitivity of the sensors, and  the ease with which they can be manufactured, could enable them to be used at home to monitor gout, diabetes, and cardiovascular diseases.


Professor Gao will be a featured speaker at Wearable Tech + Digital Health + Neurotech Silicon Valley on February 11-12, 2020.

Wireless, wearable sticker adds a sense of touch to VR

John Rogers, Yonggang Huang and Northwestern colleagues have developed an “epidermal VR” system that adds a sense of touch to any virtual reality experience.

The device incorporates a distributed array of 32 individually programmable, millimeter-scale actuators, each of which generates a discrete sense of touch at a corresponding location on the skin. Each resonates most strongly at 200 cycles per second, where the skin exhibits maximum sensitivity. The actuators are embedded into a soft silicone polymer that adheres to the skin without tape or straps. The wireless, battery-free, device communicates with a phone or tablet through near-field communication protocols.

When a user touches the screen, that pattern of touch transmits to the patch. When video chatting from different locations, users can feel each other’s touch.

The next generation will be slimmer and lighter, with actuators that can produce heating and stretching sensations.  They will eventually  be thin and flexible enough to be woven into clothes.

Click to view Nature video


Join ApplySci at the 13th Wearable Tech + Digital Health + Neurotech Silicon Valley conference on February 11-12, 2020 at Quadrus Sand Hill Road.  Speakers include:  Zhenan Bao, Stanford – Vinod Khosla, Khosla Ventures – Mark Chevillet, Facebook – Shahin Farshchi, Lux Capital – Carla Pugh, Stanford – Nathan Intrator, Tel Aviv University | Neurosteer – Wei Gao, Caltech – Sergiu Pasca, Stanford – Rudy Tanzi, Harvard – Sheng Xu, UC San Diego – Dror Ben-Zeev, University of Washington – Mikael Eliasson, Roche  – Unity Stoakes, StartUp Health

 

 

 

 

Pacifier sensor detects glucose levels in babies

UCSD’s Joe Wang has developed a soft, flexible, pacifier-based biosensor that continuously monitors glucose levels in saliva to detect diabetes in babies. Until now,  continuous glucose monitoring in newborns,  available only in major hospitals, requires piercing the infant’s skin to reach interstitial fluid.

The team created a proof of concept pacifier where small amounts of saliva were transferred through a narrow channel to a detection chamber.  An enzyme attached to an electrode strip converted glucose in the fluid to a weak electrical signal, which could be detected wirelessly by an app. The strength of the current correlated with the amount of glucose in saliva samples.

The preliminary analysis was conducted on adults with type 1 diabetes.  The pacifier detected changes in glucose concentrations in  saliva before and after a meal.

The device could also be configured to monitor other disease biomarkers.


Joe Wang will be a keynote speaker at ApplySci’s 12th Wearable Tech + Digital Health + Neurotech Boston conference on November 14, 2019 at Harvard Medical School.  

Other speakers include:  Brad Ringeisen, DARPA  – Carlos Pena, FDA  – George Church, Harvard – Diane Chan, MIT – Giovanni Traverso, Harvard | Brigham & Womens – Anupam Goel, UnitedHealthcare  – Nathan Intrator, Tel Aviv University | Neurosteer – Arto Nurmikko, Brown – Constance Lehman, Harvard | MGH – Mikael Eliasson, Roche – Nicola Neretti, Brown – R. Jacob  Vogelstein, Camden Partners – Yael Mandelblat-Cerf, Biogen

 

Wearable sensor monitors antibiotic levels in real time

Imperial College’s Timothy Rawson has developed a non-invasive microneedle bionsor patch capable of detecting antibiotic levels in the body. The goal is to reduce the need for blood sampling and analysis, optimize dosage, reduce drug-resistant infections and offer personalized drug delivery, both inside and outside of the hospital. A recent study showed that the accuracy of the real-time monitoring technology was similar to slower, periodic blood tests.

The technology has been used for continuous monitoring of blood sugar, but this is the first time it’s been used to monitor changes to drug concentrations. The researchers believe that  the sensors could form the basis of a ‘closed loop system’, like an insulin pump – where antibiotics are administered to patients, and levels are continuously monitored to optimize dosage.


Join ApplySci at the 12th Wearable Tech + Digital Health + Neurotech Boston conference on November 14, 2019 at Harvard Medical School featuring talks by Brad Ringeisen, DARPA – Joe Wang, UCSD – Carlos Pena, FDA  – George Church, Harvard – Diane Chan, MIT – Giovanni Traverso, Harvard | Brigham & Womens – Anupam Goel, UnitedHealthcare  – Nathan Intrator, Tel Aviv University | Neurosteer – Arto Nurmikko, Brown – Constance Lehman, Harvard | MGH – Mikael Eliasson, Roche – Nicola Neretti, Brown

Join ApplySci at the 13th Wearable Tech + Neurotech + Digital Health Silicon Valley conference on February 11-12, 2020 on Sand Hill Road featuring talks by Zhenan Bao, Stanford – Rudy Tanzi, Harvard – Shahin Farshchi – Lux Capital – Sheng Xu, UCSD – Carla Pugh, Stanford – Nathan Intrator, Tel Aviv University | Neurosteer – Wei Gao, Caltech

Biodegradable optical sensor monitors physiological function, can provide electrical stimulation, in brain and heart surgery

Northwestern’s John Rogers has developed a biodegradable optical sensor that can be implanted after brain injury and not require a second surgery for removal.  According to Rogers: “Optical characterization of tissue can yield quantitative information on blood oxygenation levels. Fluorescence signals can reveal the presence of bacteria as a diagnostic for the formation of an infection at an internal wound site. Fluorescence-based calcium imaging can reveal metrics of brain activity. There are also ways that light can be used to activate certain biological processes and that’s a next step for us.”

In addition to monitoring physiological function, the sensors  can be used as electrical stimulators for accelerating neural regeneration in damaged peripheral nerves, or as drug delivery agents programmed to release drugs at specific times.

The dissolvable sensors are also being used to monitor the oxygen level around the heart during surgery, and as a temporary pacemaker to deliver electrical stimulation following heart surgery.


Join ApplySci at the 12th Wearable Tech + Digital Health + Neurotech Boston conference on November 14, 2019 at Harvard Medical School featuring talks by Brad Ringeisen, DARPA – Joe Wang, UCSD – Carlos Pena, FDA  – George Church, Harvard – Diane Chan, MIT – Giovanni Traverso, Harvard | Brigham & Womens – Anupam Goel, UnitedHealthcare  – Nathan Intrator, Tel Aviv University | Neurosteer – Arto Nurmikko, Brown – Constance Lehman, Harvard | MGH – Mikael Eliasson, Roche – Nicola Neretti – Brown

Sensor tracks cerebral aneurysm hemodynamics

Georgia Tech’s Woon-Hong Yeo has developed a 3D-printed, stretchable, battery-free, wireless sensor, implanted in brain blood vessels to measure incoming blood flow, to evaluate aneurysm healing.  The tiny device wraps around stents or diverters implanted to control blood flow in affected vessels. It is believed to be the first demonstration of aerosol jet 3D printing to produce an implantable, stretchable sensing system for wireless monitoring.

Inserted using a catheter, the sensor uses inductive coupling of signals to allow wireless detection of biomimetic cerebral aneurysm hemodynamics.

Current cerebral aneurysms monitoring requires repeated angiogram imaging with potentially harmful contrast materials. Cost and potential negative effects limit the use of these techniques.  A sensor placed in a blood vessel could allow more frequent evaluations without the use of imaging dyes.


REGISTRATION RATES INCREASE SEPTEMBER 20 | Join ApplySci at the 12th Wearable Tech + Digital Health + Neurotech Boston conference on November 14, 2019 at Harvard Medical School featuring talks by Brad Ringeisen, DARPA – Joe Wang, UCSD – Carlos Pena, FDA  – George Church, Harvard – Diane Chan, MIT – Giovanni Traverso, Harvard | Brigham & Womens – Anupam Goel, UnitedHealthcare  – Nathan Intrator, Tel Aviv University | Neurosteer – Arto Nurmikko, Brown – Constance Lehman, Harvard | MGH – Mikael Eliasson, Roche

Printed stickers, stretchable antennas, fluctuation-resistant RFID for continuous whole-body monitoring

Zhenan Bao‘s adhesive, unobtrusive wearables continue to change the way health is monitored.  Her new BodyNet system tracks pulse, respiration, and other physiological signs using small, screen printed stickers around the body, and a wireless receiver clipped to clothing. The research was published in Nature Electronics last week.

Her  goal is to “create an array of wireless sensors that stick to the skin and work in conjunction with smart clothing to more accurately track a wider variety of health indicators than the smart phones or watches consumers use today.”

The technology is almost un-noticeable to the wearer, as it does not include batteries or rigid circuits. To achieve this, the Bao Lab created a new antenna that could stretch and bend like skin, and an RFID system capable of sending strong and accurate signals to the receiver, despite constant fluctuations.

The initial version of the stickers relied on tiny motion sensors. The team will next integrate sweat, temperature and other sensors.

Bao believes that “one day it will be possible to create a full-body skin-sensor array to collect physiological data without interfering with a person’s normal behavior.”


Tiny fiber optic sensor monitors blood flow in real-time

John Arkwright and Flinders University colleagues have developed a tiny, low cost, fiber-optic sensor to monitor blood flow through the aorta in real-time.  The goal is continuous monitoring during prolonged intensive care and surgical procedures.  Current blood flow measurement, using ultrasound or thermo-dilution,  is intermittent, averaging every 30 minutes.

The device is inserted through a small  aperture in the skin, into the femoral artery, when heart function is compromised.  Its size allows it to be  used in the tiny blood vessels of infants. Very young babies  are particularly susceptible to sudden drops in blood pressure and oxygen delivery to vital organs.


Join ApplySci at the 12th Wearable Tech + Digital Health + Neurotech Boston conference on November 14, 2019 at Harvard Medical School and the 13th Wearable Tech + Neurotech + Digital Health Silicon Valley conference on February 11-12, 2020 at Stanford University

Sensor glove identifies objects

In a Nature paper, the system accurately detected  objects, including a soda can, scissors, tennis ball, spoon, pen, and mug 76 percent of the time.

The tactile sensing sensors could be used in combination with traditional computer vision and image-based datasets to give robots a more human-like understanding of interacting with objects. The dataset also measured cooperation between regions of the hand during  interactions, which could be used to customize prosthetics.

Similar sensor-based gloves used cost thousands of dollars and typically 50 sensors. The  STAG  glove costs approximately $10 to produce.

Click to view MIT video


Join ApplySci at the 12th Wearable Tech + Digital Health + Neurotech Boston conference on November 14, 2019 at Harvard Medical School and the 13th Wearable Tech + Neurotech + Digital Health Silicon Valley conference on February 11-12, 2020 at Stanford University