Integrated chemical/ultrasonic transducer sensor
Disclosed are devices, systems, and methods for multi-modal, wearable sensors, including an electrochemical-ultrasonic transducer-based sensor, that can simultaneously detect and monitor one or more bio-analyte markers and one or more physiological markers. In some aspects, a wearable, acoustic-electrochemical sensor device includes a flexible substrate, one or more electrochemical sensors disposed on the flexible substrate, a physiological sensor comprising an array of acoustic transducers disposed on the flexible substrate, wherein the sensor device is operable to simultaneously detect and monitor one or more analyte markers and physiological markers including hemodynamic parameters.
1 . A wearable, acoustic-electrochemical sensor device, comprising:
a flexible substrate comprising an electrically insulative material, the flexible substrate capable of attaching and conforming to skin;
an electrochemical sensor comprising two or more electrodes disposed on the flexible substrate, the two or more electrodes including a first electrode to detect a signal associated with an analyte by an electrochemical detection, and a second electrode configured as a counter electrode or a reference electrode;
a physiological sensor comprising an array of acoustic transducers disposed on the flexible substrate and a ground wire coupled to and spanning across each acoustic transducer of the array, the array of acoustic transducers including an acoustic transduction material, wherein the physiological sensor is configured to direct acoustic signals from the array of acoustic transducers toward a blood vessel in or beneath the skin to detect a hemodynamic parameter of the blood vessel; and
an array of electrical interconnection structures disposed on the flexible substrate, wherein at least one of the electrical interconnection structures is configured as a ground electrical interconnection structure having a serpentine pattern, and wherein the ground wire of the physiological sensor includes the serpentine pattern and spans from the array of acoustic transducers to the ground electrical interconnection structure,
wherein the sensor device is operable to simultaneously detect and monitor one or more analyte markers and physiological markers.
2 . The sensor device of claim 1 , wherein the array of acoustic transducers of the physiological sensor is spaced apart from the electrochemical sensor by a distance of at least 0.1 cm.
3 . The sensor device of claim 1 , wherein the physiological sensor is configured on a first side of the flexible substrate configured to attach to the skin, and the electrochemical sensor is configured on a second side of the flexible sensor opposite to the first side, such that the electrochemical sensor is able to be exposed to a biofluid deposited on the electrochemical sensor.
4 . The sensor device of claim 1 , wherein the physiological sensor includes a hydrogel material coupled to the array of acoustic transducers and configured to propagate an acoustic signal generated at the acoustic transducers to the skin and to propagate a returned acoustic echo received from the skin to the acoustic transducers.
5 . The sensor device of claim 1 , wherein the electrochemical sensor includes a functionalization layer disposed at least partially on the first electrode that includes one or more molecules to catalyze a chemical reaction or bind to the analyte for the electrochemical detection at the first electrode, and wherein the wearable, acoustic-electrochemical sensor device further comprises:
a second electrochemical sensor comprising two or more electrodes disposed on the flexible substrate, the two or more electrodes of the second electrochemical sensor including a third electrode to detect a second signal associated with a second analyte by a second electrochemical detection, and a fourth electrode configured as a counter electrode or a reference electrode, wherein the second analyte is different than the analyte detectable at the first electrode.
6 . The sensor device of claim 1 , wherein the second electrode is configured as the reference electrode, and wherein the two or more electrodes of the electrochemical sensor include a third electrode configured as the counter electrode.
7 . The sensor device of claim 6 , wherein the two or more electrodes of the electrochemical sensor include a fourth electrode configured as an iontophoresis (IP) electrode, the IP electrode operable to facilitate extraction of interstitial fluid of the skin or induce excretion of sweat from the skin.
8 . The sensor device of claim 7 , wherein the electrochemical sensor includes a hydrogel coupled to the IP electrode, wherein the hydrogel entraps one or more chemicals able to cause extraction of the interstitial fluid or excretion of the sweat upon controlled release from the hydrogel by an electrical potential applied at the IP electrode.
9 . The sensor device of claim 6 , wherein two or more electrodes are printed electrodes, wherein the first electrode and the counter electrode comprise a Prussian Blue, and wherein the reference electrode comprise a silver ink.
10 . The sensor device of claim 1 , wherein each of the electrical interconnection structures is configured as serpentine interconnection structures that allow for stretching and bending on the flexible substrate.
11 . The sensor device of claim 1 , wherein the acoustic transduction material includes at least one of piezoelectric lead zirconate titanate (PZT), lead magnesium niobate-lead titanate (PMN-PT), or polyvinylidene difluoride (PVDF).
12 . The sensor device of claim 1 , wherein the array of acoustic transducers is configured as an array of transducer pixels comprising piezoelectric lead zirconate titanate (PZT), and wherein each transducer pixel includes an aspect ratio of 0.3 or smaller based on a height dimension to a width dimension, such that aspect ratio is able to control vibration of the acoustic transduction material to be in a thickness mode with a particular frequency or frequency range.
13 . The sensor device of claim 12 , wherein the particular frequency is 7 MHz; or wherein the frequency range includes 5 MHz to 9 MHz.
14 . The sensor device of claim 1 , wherein the flexible substrate includes at least one of a styrene-ethylene-butylene-styrene block copolymer (SEBS), a styrene-isoprene-styrene block copolymer (SIS), or a styrene-butylene-styrene block copolymer (SBS).
15 . The sensor device of claim 1 , wherein the flexible substrate includes at least one of ECOFLEX®, polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), polyurethane (PU), or polyethylene vinyl acetate (PEVA).
16 . The sensor device of claim 1 , wherein the flexible substrate is structured to include a first substrate layer and a second substrate layer that is attached to a side of the first substrate layer, wherein each of the first substrate layer and the second substrate layer comprises a first region and a second region, wherein the physiological sensor is coupled to the first region of the first substrate layer, and the electrochemical sensor is coupled to the second region of the second substrate layer, wherein the second substrate layer includes an opening at the first region such that physiological sensor is exposed through the opening of the second substrate layer.
17 . The sensor device of claim 1 , wherein the hemodynamic parameter includes blood pressure or blood flow.
18 . The sensor device of claim 1 , further comprising one or more additional sensors including a temperature sensor, an electrocardiogram (ECG) sensor, a pressure sensor, or a mechanical strain sensor.
19 . The sensor device of claim 1 , wherein the physiological sensor comprising the acoustic transducers is operable to detect blood pressure of a user of the wearable, acoustic-electrochemical sensor device, and wherein the electrochemical sensor is operable to detect lactate of the user, such that the sensor device is operable to monitor for septic shock.
20 . The sensor device of claim 1 , wherein the analyte includes lactate, cortisol, glucose, alcohol, caffeine, or an electrolyte.