Abstract: Described herein are implantable devices configured to emit an electrical pulse. An exemplary implantable device includes an ultrasonic transducer configured to receive ultrasonic waves that power the implantable device and encode a trigger signal; a first electrode and a second electrode configured to be in electrical communication with a tissue and emit an electrical pulse to the tissue in response to the trigger signal; and an integrated circuit comprising an energy storage circuit. Also described are systems that include one or more implantable device and an interrogator configured to operate the one or more implantable devices. Further described is a closed loop system that includes a first device configured to detect a signal, an interrogator configured to emit a trigger signal in response to the detected signal, and an implantable device configured to emit an electrical pulse in response to receiving the trigger signal.

Abstract: Described herein is an implantable device having a sensor configured to detect an amount of an analyte, a pH, a temperature, strain, or a pressure; and an ultrasonic transducer with a length of about 5 mm or less in the longest dimension, configured to receive current modulated based on the analyte amount, the pH, the temperature, or the pressure detected by the sensor, and emit an ultrasonic backscatter based on the received current. The implantable device can be implanted in a subject, such as an animal or a plant. Also described herein are systems including one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transmit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices. Also described are methods of detecting an amount of an analyte, a pH, a temperature, a strain, or a pressure.

Abstract: Described herein is an implantable device having a sensor configured to detect an amount of an analyte, a pH, a temperature, strain, or a pressure; and an ultrasonic transducer with a length of about 5 mm or less in the longest dimension, configured to receive current modulated based on the analyte amount, the pH, the temperature, or the pressure detected by the sensor, and emit an ultrasonic backscatter based on the received current. The implantable device can be implanted in a subject, such as an animal or a plant. Also described herein are systems including one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transmit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices. Also described are methods of detecting an amount of an analyte, a pH, a temperature, a strain, or a pressure.

Abstract: Described herein are implantable devices configured to detect an electrophysiological signal. Certain exemplary implantable devices comprise a first electrode and a second electrode configured to engage a tissue and detect an electrophysiological signal; an integrated circuit comprising a multi-transistor circuit and a modulation circuit configured to modulate a current based on the electrophysiological signal; and an ultrasonic transducer configured to emit an ultrasonic backscatter encoding the electrophysiological signal from the tissue based on the modulated current. Also described herein are systems that include one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices.

Abstract: Described herein are methods for monitoring or modulating an immune system in a subject; treating, reducing or monitoring inflammation; monitoring blood pressure; treating hypertension; or administering or adjusting a therapy for inflammation or hypertension in a patient by electrically stimulating the splenic nerve or detecting splenic nerve activity using an implanted medical device. Also described herein are implantable medical devices for performing such methods. The implanted medical device includes an ultrasonic transducer configured to receive ultrasonic waves and convert energy from the ultrasonic waves into an electrical energy that powers the device, two or more electrodes in electrical communication with the ultrasonic transducer that are configured to electrically stimulate a splenic nerve or detect a splenic nerve activity, and optionally a splenic nerve attachment member.

Abstract: Described herein is an implantable medical device that includes a body having one or more ultrasonic transducers configured to receive ultrasonic waves and convert energy from the ultrasonic waves into an electrical energy, two or more electrodes in electrical communication with the ultrasonic transducer, and a clip attached to the body that is configured to at least partially surround a nerve and/or a filamentous tissue and position the two or more electrodes in electrical communication with the nerve. In certain examples, the implantable medical device includes two ultrasonic transducers with orthogonal polarization axes. Also described herein are methods for treating incontinence in a subject by converting energy from ultrasonic waves into an electrical energy that powers a full implanted medical device, and electrically stimulating a tibial nerve, a pudendal nerve, or a sacral nerve, or a branch thereof, using the fully implanted medical device.

Abstract: Described herein is an implantable device having a sensor configured to detect an amount of an analyte, a pH, a temperature, strain, or a pressure; and an ultrasonic transducer with a length of about 5 mm or less in the longest dimension, configured to receive current modulated based on the analyte amount, the pH, the temperature, or the pressure detected by the sensor, and emit an ultrasonic backscatter based on the received current. The implantable device can be implanted in a subject, such as an animal or a plant. Also described herein are systems including one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transmit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices. Also described are methods of detecting an amount of an analyte, a pH, a temperature, a strain, or a pressure.

Abstract: Described herein is an implantable device having a sensor configured to detect an amount of an analyte, a pH, a temperature, strain, or a pressure; and an ultrasonic transducer with a length of about 5 mm or less in the longest dimension, configured to receive current modulated based on the analyte amount, the pH, the temperature, or the pressure detected by the sensor, and emit an ultrasonic backscatter based on the received current. The implantable device can be implanted in a subject, such as an animal or a plant. Also described herein are systems including one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transmit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices. Also described are methods of detecting an amount of an analyte, a pH, a temperature, a strain, or a pressure.

Abstract: Described herein are implantable devices configured to detect an electrophysiological signal. Certain exemplary implantable devices comprise a first electrode and a second electrode configured to engage a tissue and detect an electrophysiological signal; an integrated circuit comprising a multi-transistor circuit and a modulation circuit configured to modulate a current based on the electrophysiological signal; and an ultrasonic transducer configured to emit an ultrasonic backscatter encoding the electrophysiological signal from the tissue based on the modulated current. Also described herein are systems that include one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices.

Abstract: Described herein are implantable devices configured to emit an electrical pulse. An exemplary implantable device includes an ultrasonic transducer configured to receive ultrasonic waves that power the implantable device and encode a trigger signal; a first electrode and a second electrode configured to be in electrical communication with a tissue and emit an electrical pulse to the tissue in response to the trigger signal; and an integrated circuit comprising an energy storage circuit. Also described are systems that include one or more implantable device and an interrogator configured to operate the one or more implantable devices. Further described is a closed loop system that includes a first device configured to detect a signal, an interrogator configured to emit a trigger signal in response to the detected signal, and an implantable device configured to emit an electrical pulse in response to receiving the trigger signal.

Abstract: Described herein is an implantable device configured to detect impedance characteristic of a tissue.

Abstract: Described herein is an implantable device comprising a radiation-sensitive element (such as a transistor) configured to modulate a current as a function of radiation exposure to the transistor; and an ultrasonic device comprising an ultrasonic transducer configured to emit an ultrasonic backscatter that encodes the radiation exposure to the transistor. Further described herein is an implantable device comprising a radiation-sensitive element (such as a diode) configured to generate an electrical signal upon encountering radiation; an integrated circuit configured to receive the electrical signal and modulate a current based on the received electrical signal; and an ultrasonic transducer configured to emit an ultrasonic backscatter based on the modulated current encoding information relating to the encountered radiation.

Abstract: Described herein is an implantable device having a sensor configured to detect an amount of an analyte, a pH, a temperature, strain, or a pressure; and an ultrasonic transducer with a length of about 5 mm or less in the longest dimension, configured to receive current modulated based on the analyte amount, the pH, the temperature, or the pressure detected by the sensor, and emit an ultrasonic backscatter based on the received current. The implantable device can be implanted in a subject, such as an animal or a plant. Also described herein are systems including one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transmit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices. Also described are methods of detecting an amount of an analyte, a pH, a temperature, a strain, or a pressure.

Abstract: Described herein is an implantable device having a sensor configured to detect an amount of an analyte, a pH, a temperature, strain, or a pressure; and an ultrasonic transducer with a length of about 5 mm or less in the longest dimension, configured to receive current modulated based on the analyte amount, the pH, the temperature, or the pressure detected by the sensor, and emit an ultrasonic backscatter based on the received current. The implantable device can be implanted in a subject, such as an animal or a plant. Also described herein are systems including one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transmit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices. Also described are methods of detecting an amount of an analyte, a pH, a temperature, a strain, or a pressure.

Abstract: Described herein is an implantable device having a sensor configured to detect an amount of an analyte, a pH, a temperature, strain, or a pressure; and an ultrasonic transducer with a length of about 5 mm or less in the longest dimension, configured to receive current modulated based on the analyte amount, the pH, the temperature, or the pressure detected by the sensor, and emit an ultrasonic backscatter based on the received current. The implantable device can be implanted in a subject, such as an animal or a plant. Also described herein are systems including one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transmit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices. Also described are methods of detecting an amount of an analyte, a pH, a temperature, a strain, or a pressure.

Abstract: Methods, systems, and compositions are provided for implanting an implantable device into a biological tissue (e.g., muscle, brain). A subject implantable device includes: (i) a biocompatible substrate, (ii) a conduit (e.g., an electrode, a waveguide) that is disposed on the biocompatible substrate, and (iii) an engagement feature (e.g., a loop) for reversible engagement with an insertion needle. The biocompatible substrate can be flexible (e.g., can include polyimide). The implantable device is implanted using an insertion needle that includes an engagement feature corresponding to the engagement feature of the implantable device. To implant, an implantable device is reversibly engaged with an insertion needle, the device-loaded insertion needle is inserted into a biological tissue (e.g., to a desired depth), and the insertion needle is retracted, thereby disengaging the implantable device from the insertion needle and allowing the implantable device to remain implanted in the biological tissue.

Abstract: Described herein is an implantable device having a sensor configured to detect an amount of an analyte, a pH, a temperature, strain, or a pressure; and an ultrasonic transducer with a length of about 5 mm or less in the longest dimension, configured to receive current modulated based on the analyte amount, the pH, the temperature, or the pressure detected by the sensor, and emit an ultrasonic backscatter based on the received current. The implantable device can be implanted in a subject, such as an animal or a plant. Also described herein are systems including one or more implantable devices and an interrogator comprising one or more ultrasonic transducers configured to transmit ultrasonic waves to the one or more implantable devices or receive ultrasonic backscatter from the one or more implantable devices. Also described are methods of detecting an amount of an analyte, a pH, a temperature, a strain, or a pressure.

Abstract: A power generation system produces electrical power from the flow of a fluid, such as water. Particularly, the fluid flow may be driven by evaporation of the fluid. A conduit for conveying the fluid is defined through a substrate includes at least one opening for allowing evaporation of the fluid. A dielectric substance is disposed within the conduit and impelled through the conduit by the evaporation of the fluid. The dielectric substance has a permittivity different from the permittivity of the fluid. A variable capacitor has a first plate and a second plate separated by the conduit. As such, the capacitance of the variable capacitor varies as the fluid and the dielectric substance flow between the plates. A charge pump circuit is electrically connected to the variable capacitor to store charge generated by the variable capacitor into a storage capacitor.