JP2011509216A - Insect flight control system - Google Patents

Abstract

  Insect remote control flight including start, stop, pitch control, and steering using a microcontroller driven neural stimulation system powered by a microbattery. In some embodiments, attached to the anterior chest backplate comprising a neurostimulator, a muscle stimulator, a microcontroller, and a microbattery that allows continuous remote flight control of a 2 gram Cotinis texana. A small system is provided. Flight start, stop, and lift control is achieved through neural stimulation of the brain that induces, suppresses, or changes heel vibration. The turn is triggered through direct muscle stimulation to either flight muscle. Stimulation potential (| 3 | V) and power (average 80 μW per pulse) allow an operating time longer than 31 hours when a 160 mg microbattery is mounted. Flight instructions can be preloaded into the microcontroller memory or can be remotely controlled.

Description

  This application claims the benefit of Patent Document 1 filed on Jan. 11, 2008. The entire disclosure of the above application is incorporated herein by reference.

Government Rights This invention was made with government support under N66001-07-1-2006 awarded by NAVY / SPAWAR. The government has certain rights in the invention.

  The present disclosure relates to micro air vehicles (MAVs) and nano air vehicles (NAVs), and more particularly to implantable tetherless microsystems for controlling insect flight. .

US Provisional Application No. 61 / 020,499

  In accordance with the principles of the present teachings, there is provided a miniature control system attached to the front chest back plate that includes a neurostimulator, a muscle stimulator, a microcontroller, and a microbattery that enables continuous flight control of insects. The In some embodiments, flight start, stop, and lift control is achieved through neural stimulation of the brain that will induce, suppress, and / or change heel vibration. In some examples, the turn can be triggered through direct muscle stimulation to either flight muscle. In some embodiments, a stimulation potential of about | 3 | V and a power of about 80 μW per pulse allows for an operating time longer than 31 hours with a 160 mg microbattery. Flight instructions can be preloaded into the microcontroller memory and / or can be transmitted wirelessly from a remote controller.

  Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration and are not intended to limit the scope of the present disclosure.

  The drawings described herein are solely for the purpose of illustrating selected embodiments and are not necessarily intended to describe all possible implementations and are not intended to limit the scope of the disclosure. .

FIG. 6 is a photograph showing an insect flight control system according to the principles of the present teachings attached to a Cotinis texana (Green June Beetle). FIG. 6 is a series of graphs shown side by side comparing the voltage applied to a neural electrode with a normalized audio recording of a tethered insect (Coleoptera). It is a graph during a period of alternating between stimulated flight and unstimulated flight, showing that neural stimulation causes a change in the pitch of the beetle in flight perceived as an increase in the angle of attack of a beetle with a gimbal attached The horizontal line represents the duration of stimulation (3 seconds) and the same 1 Hz, 3 V bipolar square wave as in FIG. 2 is applied during the duration of stimulation. It is a photograph of a beetle with a gimbal attached without stimulation. FIG. 5 is a photograph of a beetle with a gimbal attached in a stimulated state, further including an LED indicator representing the stimulus. It is a top view which shows the beetle flight profile (right direction change) in response to irritation | stimulation of the left flight muscle. It is a top view which shows the beetle flight profile (random flight) which responded unstimulated. It is a top view which shows the beetle flight profile (left direction change) which responded to the stimulus of the right flight muscle. FIG. 6 shows an accurate wave measured as a response to a potential pulse (3V, 0.1 Hz) applied to a beetle brain. FIG. 3 shows a test gimbal used in connection with the present teachings. It is a figure which shows the X-ray image and white light image of the nerve probe embedding to the beetle's pupa and the adult. It is a figure which shows the X-ray image and white light image of the nerve probe embedding to the beetle's pupa and the adult. It is a figure which shows the X-ray image and white light image of the nerve probe embedding to the beetle's pupa and the adult. It is a figure which shows the X-ray image and white-light image of a beetle's pupa and a silicon chip embedding to an adult. It is a figure which shows the X-ray image and white-light image of a beetle's pupa and a silicon chip embedding to an adult. It is a figure which shows the X-ray image and white-light image of a beetle's pupa and a silicon chip embedding to an adult. It is a figure which shows the X-ray image and white light image of LED embedment in a beetle's pupa and an adult. It is a figure which shows the X-ray image and white light image of LED embedment in a beetle's pupa and an adult. FIG. 3 shows an assembled visual stimulator mounted on a beetle in accordance with the principles of the present teachings. FIG. 3 shows an assembled visual stimulator mounted on a beetle in accordance with the principles of the present teachings. FIG. 3 shows an assembled visual stimulator mounted on a beetle in accordance with the principles of the present teachings. It is sectional drawing of a Michigan nerve probe. 9B is a photograph of the Michigan neuroprobe of FIG. 9A. FIG. 4 is an enlarged view of a probe tip showing a plurality of stimulation sites. It is a figure which shows one step in a series of preparation steps for forming a Michigan nerve probe. It is a figure which shows one step in a series of preparation steps for forming a Michigan nerve probe. It is a figure which shows one step in a series of preparation steps for forming a Michigan nerve probe. It is a figure which shows one step in a series of preparation steps for forming a Michigan nerve probe. It is a figure which shows one step in a series of preparation steps for forming a Michigan nerve probe. It is a figure which shows one step in a series of preparation steps for forming a Michigan nerve probe. It is a figure which shows one step in a series of preparation steps for forming a Michigan nerve probe. It is a figure which shows one step in a series of preparation steps for forming a Michigan nerve probe. It is a figure which shows a nerve stimulation waveform. FIG. 11B shows audio track recording in response to application of the neural stimulation waveform of FIG. 11A. It is a plot explaining the relationship between the yaw angle measurement of the beetle which responded to LED display, and time. FIG. 2 illustrates a remotely controlled flight control system in accordance with the principles of the present teachings. FIG. 2 illustrates a remotely controlled flight control system in accordance with the principles of the present teachings. 1 is a circuit diagram of an RF receiver assembly in accordance with the principles of the present disclosure. FIG. 2 is a photograph of a control system according to the principles of the present teachings. 2 is a photograph of a control system according to the principles of the present teachings. It is a photograph which shows the implantation site | part of a brain and an optical lobe (optic lobe). It is a photograph which shows the sagittal section (sagital section) of the anterior chest back plate | board (pronotum) which shows a posterior front chest back board (poster pronotum) embedding (counter electrode). FIG. 6 is a photograph showing the anterior chest dorsal plate also showing the basallar muscle stimulator and associated internal regions, where the proximal segmental muscle stimulator is from the rostral to the tail on either side of the insect (Caudal), inserted approximately 1 cm deep between the sternum and backplate of the anterior chest dorsal plate, the letter X and the line segment, respectively, Indicates the embedding length. It is a figure which shows the pulse train (100 Hz) with which the positive potential and negative potential which are applied between the left visual lobe and the right visual lobe for the start of flight alternate. It is a figure which shows the typical current wave observed when the pulse train of FIG. 16A is applied. FIG. 4 shows a positive potential pulse train (100 Hz) applied between either the left or right proximal flight muscle and the posterior anterior chest back plate (counter electrode) to induce a turn. is there. It is a figure which shows the typical current wave observed when the pulse train of FIG. 16C is applied. It is a photograph of the position where it stopped. It is the photograph in which LED which shows the start of irritation is lit. This is a photograph in which the kite was unfolded 0.27 seconds after the control signal was transmitted and the flight was started. It is a photograph showing the flight path of a wirelessly controlled beetle, where the beetle is initially flying toward the operator, T ₀ (0.00 seconds) is the start time of imaging, and T ₁ (0.6 Second), the operator sends a left turn signal from the base station (right proximal segment muscle stimulation), and at T ₂ (1.6 seconds), the operator stimulates the left proximal segment from the right side. When switching to the flight muscle, the beetle turns to the right and at T ₃ (3.1 seconds), the right proximal segmental flight muscle is stimulated (turns to the left) and at T ₄ (4.2 seconds), When the left basal segment flight muscle was stimulated, it turned to the right again, and at T ₅ (4.8 seconds), the beetle touched the curtain and stopped flying.

  Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

  Examples of embodiments will now be described more fully with reference to the accompanying drawings.

I. General aspects Micro-aircraft (MAV) and nano-aircraft (NAV) are defined as aircraft with a total mass of less than 100 g and a wingspan of less than 15 cm, and are the subject of intense research and development. Despite major advances, MAV and NAV still present significant tradeoffs between payload, flight distance, and speed. Currently, the main limiting factors are the energy density and power density of existing fuel sources and flight dynamic efficiency. However, many species of insects, including flies (Diptera), moths (Lepidoptera), dragonflies (Coleoptera), and beetles (Coleoptera), are currently not comparable to artificial aircraft of similar size , Providing sufficient platform for controlled insect flight with flight performance (measured by distance and speed vs load capacity and maneuverability). Thus, these and similar insects can be used in accordance with the present teachings. Both flight mechanics and the neurophysiology of some of these organisms—primarily grasshoppers, fruit flies, and moths—are now relatively well understood.

  Although flying insects can be used in accordance with the principles of the present invention, the focus of this description is on beetles. Beetles are the main reason for choosing beetles because there are more species than other organisms. Their size is in the range of about 1 mm to 10 cm, thus providing a wide choice as a research platform. A powerful air vehicle can generally achieve an average speed of about 2-6 km / hour over a duration of 10 minutes to 3 hours, allowing a maximum speed of 7-14 km / hour. Beetles experience a complete transformation and can use it to embed the flight control system. In addition, beetles are easy to breed and are generally harmless to humans.

  In general, insect flight control requires a) on-demand flight start and stop, b) altitude adjustment, and c) attitude adjustment. Tetherless maneuver further requires a means of communication between the insect and the controller or pre-programmed flight instructions loaded prior to takeoff.

  In some embodiments, as shown in FIG. 1, the control system 10 for insect flight includes a programmable microcontroller 12 powered by a microbattery 14, such as a rechargeable lithium ion coin cell. Can do. Recent advances in low-power electronics require less than 100 mg in mass, consume less than 900 μW during active operation (0.9 nJ / operation @ 1 MHz), and only 1.5 μW during standby operation The class of microcontrollers that do not do so is now available as a commercial product. This is a commercial battery larger than 3V with an energy density greater than 230 J / g and a total mass of less than 160 mg, with an operating life ranging from 11 hours (continuous active operation) to 6800 hours (continuous standby operation). enable. The electrical signals generated by the microcontroller 12 drive the silver wire electrodes 16 and 18 (φ75 μm) inserted into the brain and flight muscle and the counter electrode 20 inserted into the front chest back plate for all stimuli. In some examples, the control system 10 can weigh 230 mg or less.

As shown in FIG. 2, a 3V potential pulse applied to the brain (average power consumption of 80 μW per pulse) can induce or inhibit flight depending on polarity. In many species of insects, a reaction time (t _tag ) of about 150 ms is experienced between the onset of stimulation and the onset of vibration. If the period between pulses is shorter than t _tag , the beetle may not be able to start or stop the wing movement sufficiently, but the oscillation frequency can be changed by the stimulation frequency. In many species of insects, moths exhibit a mechanical vibrational response without vibrating neural inputs. Instead, neural signals from the brain cause the start or stop of flight behavior, prolonging the activation of antagonistic muscle groups, thereby producing a rhythmic flight output.

In some embodiments of the present teachings, particularly with respect to Cotinis texana, an input signal applied to the brain induces or stops flight behavior depending on the polarity of the stimulus. The start or stop of flight due to a stimulus occurs regardless of whether the beetle has stopped, is strongly or weakly tethered, or is flying freely. The beetle can stop flying in the air, or the beetle can try to vibrate the moth even if it is overloaded so that flight is not possible. Bipolar pulse trains change wrinkle vibration when the interval between pulses is shorter than the beetle reaction time (FIG. 2). The soot oscillator system basically receives “on” and “off” cues faster than it can react to them, so that the soot oscillator frequency is mixed with the stimulation frequency. In some embodiments, the first 700 ms (t _{enhanced in} FIG. 2) has been confirmed that stimulating wrinkle movements generate acoustic signatures with significantly larger amplitudes, so that in their initial flapping, This suggests that more energy is available. This phenomenon is used to control lift and thrust during flight. Beetles always rose when a 10 Hz potential pulse train was applied to the brain, and returned to normal flight when no stimulation was applied (FIG. 3).

  The turn was triggered by independent stimulation of the left and right flight muscles using a positive potential pulse train. In Cotinis texana, the flight muscle contracts and extends normally at 76 Hz when stimulated by a 6 Hz nerve impulse from the beetle nervous system. The Cotinis texana flight muscle has been reported to produce maximum power when directly stimulated by electrical pulses with a frequency of 100 Hz. During flight, turning can be caused by applying a 100 Hz, 2 V potential pulse train to the flight muscle opposite to the intended turning direction (FIG. 4). That is, a right turn can be caused by stimulation of the left flight muscle, which produces more power than the right flight muscle and consequently causes a right turn, but the right flight muscle electrode is the counter electrode The same potential as 20 is maintained. The total angle of flight rotation can be set by the duration of the stimulus.

  In summary, the present teachings can control 2 grams of insects in flight with multiple degrees of freedom for longer than 24 hours. In fact, in some embodiments, the control system 10 can be constructed from commercially available components and can be embedded using a drilling tool with basic knowledge of insect anatomy.

II. General Materials and Methods A) Breeding of Cotinis texana Cotinis texana (2-4 cm, 1-2 g of Scotch) was collected in an orchard in Texas, USA. Beetles were placed in groups of 30 to 40 terrestrial incubators (40 cm × 27 cm × 32 cm) containing organic peat to a quarter of the total volume, and sliced apples were fed once a week. The temperature was kept at about 28 ° C. during the day using an incandescent bulb placed on a terrestrial incubator, and the same bulb maintained a 15 hour day / 9 hour night cycle. The wall of the terrestrial incubator was covered with black paper on the outside. In order to keep the humidity around 60%, moisture was sprayed on the peat every day.

B) Measurement of load capacity The load capacity of beetles is determined by tying a single string around the beetle's torso between the anterior chest back plate and thorax, and a ring is made at the other end of the string It was. Beetles were allowed to fly freely. Several thin metal wires, each weighing 10 mg, were added in stages to the beetle's center of mass until the beetle lifted its weight and could not fly. Thereafter, the total weight of the added thin metal wires was measured and recorded as the loading capacity.

C) Stimulator assembly Prior to assembly, in some examples, each microcontroller (Texas Instruments, MSP430F2012IPWR, 63 mg, 5.0 mm x 4.5 mm x 1.0 mm) was assembled into a TI MSP430 14 Pin Package Board and The flight program was preloaded using an interface with a USB Programmer (MSP-FET430U14). After loading, six silver wires (φ75 μm) were soldered to different pins of the microcontroller. In some cases (similar to FIG. 3), a small LED (Lite-On Inc., LTST-C171GKT, 3 mg, 2.0 mm × 1.2 mm × 0.7 mm) is also soldered in parallel as a stimulus indicator. It was attached. Surface mounted resistors (10 KΩ, each less than 1 mg) were soldered in parallel to adjust the potential applied to other than the 3 V potential initially supplied from the microbattery. A microbattery (Panasonic, ML614, 3V, 160 mg, φ6.8 mm × 1.4 mm, 3.4 mAh) was attached to the microcontroller using a 1 mm × 1 mm double-sided adhesive tape. The assembly was attached to the Cotinis texana front chest back using beeswax. Four small holes are carefully inserted into the epidermis skin of the beetle at the front chest back plate behind the microcontroller, a) the middle of the head between the compound eyes, b) the flight muscles on both sides, and c) It was opened. Four of the wires were inserted through the holes. The remaining two wires were connected between the VDD pin and GND pin of the microcontroller and the anode terminal and cathode terminal of the microbattery, respectively. On average, beetles lived longer than two weeks with an assembled flight control system.

D) Calculation of power consumption The current flowing through the body of a beetle during stimulation was measured using an ammeter (Keithley, 6485 Picoammeter) and a function generator (Agilent, 33220A) was applied to the beetle brain with a potential pulse (3V, 0.1 Hz) was applied. A typical measured current wave is shown in FIG. An average of 80 μW was consumed during the stimulation pulse. Given this and an average operating power consumption of 250 μW for the microcontroller, the microbattery at 3.4 mA can maintain a continuous stimulus for 31 hours. Of course, since the stimulus is sent as a 20% duty cycle pulse train (FIG. 2), battery life can be significantly increased.

E) Beetle Flight Record All beetle flight was recorded in a closed room with temperature and humidity kept at 28 ° C. and 60%, respectively. Beetle flight can be in three states: a) tethered to the tip of a small rod, b) tied to a string, or c) a flying beetle rotating around a single axis Recorded in one of the states glued to a custom flexural gimbal (FIG. 6). The gimbal 100 is connected by a silicone elastomer flexure 106 (PDMS, polydimethylsiloxane) having a known torsional stiffness constant (kθ = 3.32 × 10 −5 Nm / rad). In addition, a machined acrylic inner 102 and an outer ring 104 may be included. The edge of the outer ring 104 was supported horizontally by a lab jack.

  Before the insects fly, the beetles are attached to the center pole 108 of the inner ring 104 so that the inner ring makes an initial angle of −25 degrees with respect to the horizontal (FIG. 6). The inner ring showed an angle between 10 and 20 degrees with respect to the horizontal (FIG. 3). A color dot was painted on one corner of the inner ring and each frame was digitized. To track the change in ring angle relative to the horizontal, the gimbal rotation angle was extracted from the marker motion relative to the center of rotation (set by the user) using a custom code from MATLAB (The Mathworks). . Beetle flight can be done with a video camera (Victor, GZ-MG275-S, 30 frames per second, shutter speed 1 / 2-1 / 4000 seconds, resolution 720 × 480 pixels) or a high-speed camera (Motion Engineering, FASTCAM-X 1024PC1). , 6000 frames per second, shutter speed 1/6000 sec, resolution 256 × 256 pixels). The frame rate of the high speed camera was about 85 times the wing beat rate. A high speed camera can be used to record the flapping frequency and the delay between the stimulus (indicated by the LED indicator, see eg FIG. 3) and the response.

F) Implantation studies In some embodiments, some or all of the components of the flight control system 10 can be implanted in insects. To achieve this goal, a silicon tip (1.5 mm x 3.0 mm x 0.5 mm), a silicon neuroprobe / stimulator, and a microfluidic glass tube (φ200 μm) are used for surgical infringement of beetles on pupae. In order to determine if they are generally resistant to, they were implanted in the pupal stage Zophobas mori beetle. As Cotinis texana was utilized for microcontroller flight experiments, Zophobas mori, which is readily available in large numbers and has a shorter breeding period, can also be utilized. At each implantation, a cut was made in the pupa's epidermis at the target location using a precision micro scissor. A silicon chip is carefully removed from the cut under the pupal epidermis at the dorsal abdomen, the anterior chest dorsal plate, the ventral abdomen, or the ventral anterior chest dorsal plate. Was inserted. A neuroprobe was inserted through the incision into the brain at exactly the same location as the wire electrode used elsewhere in this specification. A microfluidic glass tube was inserted into the anterior chest backplate. As a result, most pupae successfully emerged as normal adults. The success rates and average lifetimes for all implants are summarized in Table 1. Success rate is defined as the ratio of normal emergence to all emergence, including malformations.

  7A-7H show representative embedded X-ray and white light images in both the pupa stage and the adult stage. Specifically, FIGS. 7A-7C illustrate beetle pups and neural probe implantation in adults. Figures 7D-7F show beetle pups and silicon chip embedding in adults. 7G and 7H show the LED embedding in the puppet stage and the function of the LED in the adult stage. In some embodiments, a pupa epidermis (later an adult epidermis) is used to test whether an electrical connection with the implanted device is possible, so that the LED is implanted and provides visual confirmation. Flashed through.

III. First Case Study A) Stimulator Assembly In FIGS. 8A-8C, the case study microsystem is shown, at least in part. The nerve stimulation system 200 (FIG. 8A) includes four types of nerve stimulators, which are thin silver wire electrodes (φ75 μm), one (200) implanted on the back side behind the eye and one (204 ) Is embedded in the flight control region of the insect brain, two (206) are embedded under the flight muscles on both sides so as to extend from the front to the rear, and the fourth (208) is the front chest It was inserted into the back plate and used as a counter electrode. The visual stimulator 210 (FIGS. 8B and 8C) comprises one or more white SMT LEDs 212 (light emitting diodes, LTST-C171 YKT) mounted on a polyimide flexible PCB (printed circuit board) 214. Can do. The microcontroller 216 can drive the LED 212 via metal wiring on the polyimide. Both neurostimulators and visual stimulators are driven by a microcontroller (Texas Instrument, MSP430), and some characterization can be done by a function generator. The flight command sequence can be stored in 2 KB of memory (the current program's flight commands are approximately 1000 commands). A Michigan neuroprobe (FIGS. 9A-9C) with a flexible parylene cable can be made and mounted on a polyimide PCB with a microbattery. The process of making the neural probe is shown in FIG.

B) Flight Control As described herein, successful flight control requires on-demand flight start and stop, as well as direction and acceleration control. 11A and 11B show the start of flight results using a brain stimulator, FIG. 11A shows the nerve stimulation waveform, and FIG. 11B shows the flapping audio track recording. Briefly, in some embodiments, a negative voltage pulse of about 1.5V has been found to start the heel muscle vibration, and a similar positive potential pulse has been found to stop the heel muscle vibration. This can be repeated virtually indefinitely or until exhausted. Interestingly, in some embodiments, the first 0.3 seconds of any flight was found to produce a larger amplitude and then decay to steady state. This means that fast “switching” (greater than about 2 Hz) produces a flapping amplitude that is slightly greater than normal undisturbed flight. If the timing of the pulses with alternating polarity is adjusted well enough, the oscillator will not be able to turn on or off completely, but will be able to vary with the applied pulse frequency. For flying beetles, this causes controllable changes in thrust and lift. A beetle was attached to the gimbal 100 (FIG. 6) to quantify changes in lift and thrust. A stimulus signal of 10 Hz with a duration of 3 seconds, similar to that of FIG. 11A, induced an increase in thrust and lift. Changes in left and right heel vibrations were achieved using the heel muscle nerve stimulator. After the heel vibration has begun, the muscle stimulator (+ 1V, 100 Hz) can change the amplitude of either heel.

  The average power consumption of the stimulator was 80 μW in the worst case of 10 nerve pulses per second, and the average consumption of the microcontroller was determined to be 250 μW. Thus, a 3.7 mAh microbattery can supply power for 31 hours under these conditions.

C) Optical stimulator In some examples, optical stimulation was explored as an alternative to flight control. The initial characterization is a series of using DLP on a paper screen placed approximately 15 cm in front of Cotinis texana attached to gimbal 100 (rotated 90 degrees to allow yaw or roll rotation). This was done by projecting black and white vertical stripes. During flight, all beetles (N> 15) consistently tracked the movement of the stripes with the head, then started to turn and the delay in turning was generally about 2 seconds . This same phenomenon has been shown and characterized in fruit flies. A miniature optical stimulation system is shown in FIGS. 8B and 8C. In some examples, three rows of 10 LEDs were driven by a microcontroller. Each row of LEDs can be lit independently to create the illusion of movement. The base of the device can be attached to the beetle front chest back plate and the array of LEDs can be hung in front of the beetle head. The response to optical stimuli using current devices varies from beetle to beetle and is susceptible to interference by ambient light. There was a beetle that showed a large turnaround reaction, but it was in the dark.

  FIG. 12 provides data on a representative experiment that illustrates the relationship between beetle yaw angle measurement in response to LED display and time. In this experiment, the beetle and optical stimulation device were mounted on a small ball bearing that allowed continuous yaw rotation about the beetle's vertical axis in the dark. The device alternately turns on the left LED (6 seconds), shifts the lighting to the right side (0.5-1.5 seconds), lights the right side (6 seconds), and then returns to the left side (0. This sequence was repeated indefinitely for 5 to 1.5 seconds. In this experiment, beetle flight was consistently redirected away from the side of the lit LED. A delay of up to 4 seconds was observed between the time when the LED changed side and the time when the beetle began to turn away from the LED. A larger experiment (number of beetles N> 20, number of different LED actuation patterns M> 10) showed that the visual motion gradient between the sides, the frequency of LED changes, and the number of lit LEDs (ie the apparent size of the bright spot) ) Was executed in various ways. With the exception of the above stimuli, none of the reactions caused by the change were correlated with the stimulus.

D) Implantation Various silicon chips, neuroprobes, and microfluidic tubes were introduced into the pupal stage beetle to determine the ideal implant size and position (Figure 7 and Table 1). FIG. 7 shows an X-ray image and a white light image for a representative implant in both the pupa stage and the adult stage. In order to characterize the electrical connections, encapsulated SMT LEDs were embedded in pupae and bonded to a commercial pin header that protruded from the epidermis. The epidermis fused with the pin header during puppeting. After emergence, the header was used to flash the internal LEDs (3V, 1mA) without adversely affecting the insects.

E) General Conclusion In accordance with the present teachings, an implantable flight control microsystem for beetles is disclosed that is capable of changing flight start, stop, acceleration / climbing, and turning. The system consists of a number of inserted nerve and muscle stimulators, visual stimulators, polyimide assemblies, and microcontrollers, and can operate for more than a day while providing continuous stimulation to beetles. The system can be powered by two size 5 spiral microbatteries. The insect platform was a Cotinis texana-2 cm long, 1-2 gram long-tailed frog-although alternative insects can be used.

IV. Second Case Study In some embodiments, the ability to remotely control insect flight and receive information from onboard sensors (ie, cameras, detectors, sensors, etc.) is an entertainment, reconnaissance, rescue, and testing It was confirmed that it can be applied to a wide variety of applications including Furthermore, in biology, the ability to control insect flight is the ability of insect predators, such as birds, to perform research on insect signaling, mating behavior, and flight energetics, and ground robots. Useful for foraging behavior studies. In engineering, electronically controllable insects can be useful models of MAV and NAV that mimic insects. Furthermore, the tetherless electrically controllable insects themselves can be used as MAVs and NAVs and serve as couriers to places where humans or ground robots are not easily accessible.

B) RF system The remote control system of this case study comprises two Chipcon Texas Instruments CC2431 microcontrollers (6x6mm, 130mg, 2.4GHz), one functioning as a beetle-mounted RF receiver, One functions as a computer-driven RF transmitter base station. Based on the schematic shown in FIG. 14A, a custom PCB (printed circuit board, 16 × 13 mm, FR4 (hard) version: 500 mg, polyimide (flexible) version: 70 mg) is designed and manufactured for the receiver. It was done. After programming, the microcontroller and other components were assembled on the PCB as shown in FIG. 14B. The microcontroller is a rechargeable micro lithium polymer battery (Micro Avionics, 4V, 8) that is attached to the backside of the PCB with double sided adhesive tape as shown in FIG. 14C and electrically connected to the PCB in use. At 350 mA) at 5 mA. The total weight of the assembly was approximately 1331 mg, of which 687 mg was PCB and miscellaneous components, 350 mg was a microbattery, 74 mg was an antenna, 130 mg was a microcontroller, and 90 mg was an adhesive.

  The beetle Mecynorhina polyphemus or Mecynorhina torquata (4-10 g, 4-8 cm) was used as the insect platform. The assembly was attached to the beetle's posterior front chest back plate (FIGS. 13A-13B) and glued using beeswax. The ends of the six output wires from the assembly are the left optic lobe 402 and right optic lobe 404, brain 406, posterior anterior chest back plate 408, left proximal segmental flight muscle 410 and right proximal segmental flight muscle 412. (FIGS. 15A to 15C).

  Flight commands are generated by custom control software (BeetleCommander v1.0) running on a personal computer that interfaces with a transmitter (CC2431 microcontroller mounted on a Chipcon Texas Instruments SmartRF 04EB) via a USB port. It was. BeetleCommander v1.0 allowed in-flight control of stimulation parameters including the frequency, number, and duty cycle of control voltage pulses to the stimulation site. The signal is broadcast on a single channel (1A, 2.480 GHz) using direct sequence spread spectrum RF modulation, CC 2431 built-in 2.4 GHz IEEE 802.15.4. Sent using a compliant transmitter. It should be understood that alternative transmission protocols can be used. When the transmitter was instructed to do so, it sent commands to the receiver every 1 ms for 300 ms. The flight commands were mapped to the appropriate voltage pulse trains on the beetle neural stimulator by custom signal generation software (BeetleBrain v1.0) running on the receiver. A surface mount resistor was soldered in parallel as a voltage divider to each output pin to adjust the applied potential to a value other than 4V supplied from a lithium polymer battery.

  The operating range of the beetle-mounted radio system was about 10 m indoors in the current office environment and about 20-50 m outdoors depending on the line of sight and the presence. At full power, the receiver consumes about 77 mW. When the sleep mode and the reception mode are periodically repeated, the consumption during operation is 10.95 mW. The optic lobe stimulation and the proximal nodal flight muscle stimulation consumed about 500 μW and about 20 μW, respectively, as shown in FIGS. 16A-16D.

C) Flight control The start of flight is performed by using two neural stimulators (FIGS. 13, 15A, and 15C) embedded in the optic lobe via an on-board receiver, 4V, 100 Hz, duty cycle 20% positive. It was caused by applying a pulse train with alternating potential and negative potential (FIGS. 16A and 16B). The reaction time was less than 1 second (N = 9) and was determined by analyzing a 30 fps video frame by frame as shown in FIGS. The beetle responded to the flight start command in 270 ms. Flight arrest was caused by a single 4V, 1 second pulse applied during the optic lobe.

The direction change during free flight is a positive potential pulse of 2 V, 100 Hz with respect to the posterior anterior chest back plate (opposite electrode) on either the left or right proximal segmental flight muscle (working electrode) (FIG. 16C and FIG. 16D) could be induced. The beetle turned in the opposite direction to the stimulated side, for example, a left turn was triggered by stimulating the right proximal segmental flight muscle. A typical turn control is shown in FIG. 18, where the beetle was initially flying towards the operator. T ₀ (0.00 seconds) is a shooting start time. At T ₁ (0.6 seconds), the operator sent a left turn signal (right proximal segmental muscle stimulation) from the base station. At T ₂ (1.6 s), the beetle turned to the right when the operator switched the stimulating side from the right side to the left proximal nodal flight muscle. At T ₃ (3.1 seconds), the right proximal segmental muscle was stimulated (turning left). At T ₄ (4.2 seconds), when the left proximal segmental muscle was stimulated, it turned to the right again. At T ₅ (4.8 seconds), the beetle touched the curtain and stopped flying.

D) Conclusion According to the principles of the present teachings, the first wireless flight control microsystem is provided that uses a small RF receiver mounted on a living insect and an RF transmitter operated from a base station. Flight start and stop was achieved by neural stimulation of both optic lobes, and free flight direction change was induced by muscle stimulation of either the left or right proximal segmental flight muscle.

  The foregoing description of the examples has been provided for purposes of illustration and description. The above description is not intended to be exhaustive or to limit the present invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but can be interchanged and selected where applicable, even if not specifically shown or described. Can be used in other embodiments. The same can be diversified in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.

Claims (16)

A control system for controlling the flight of insects,
A plurality of stimulators implantable in the insect;
Power supply,
A controller operatively coupled to the power source and the plurality of stimulators for outputting a control signal to the plurality of stimulators in response to a control input to induce a controlled flight of the insects. Control system.   The control system of claim 1, wherein the plurality of stimulators include neural probes that are implantable in the insect brain.   The control system of claim 2, wherein the control signal output through the neural probe is operable to change the angle of attack of the insect.   The control system of claim 1, wherein the plurality of stimulators includes a pair of flight muscle stimulators that are implantable in opposing flight muscles of the insect.   The control system of claim 4, wherein the control signal output through the pair of flight muscle stimulators is operable to change a horizontal direction of the insect flight.   The control system of claim 4, wherein the controller is operable to output the control signal to only one of the pair of flight muscle stimulators.   The control system of claim 1, wherein the plurality of stimulators include stimulators operably connectable to the insect visual lobe.   The control system of claim 1, wherein the plurality of stimulators comprises stimulators that are implantable in the insect's front chest back plate.   The control system of claim 1, wherein the controller is disposed substantially within the insect body structure. The control system of claim 1, further comprising a visual stimulator visible to the insect, the visual stimulator coupled to the controller for outputting a visual cue to the insect.   The control system of claim 1, wherein the plurality of stimulators includes a neural probe having a plurality of stimulation sites disposed along a longitudinal direction. A receiver operably coupled to the controller;
A remote controller wirelessly coupled to the receiver, the remote controller operable to transmit the control input to the receiver such that the receiver communicates the control input to the controller; The control system according to claim 1, further comprising: The control system of claim 1, further comprising a memory device coupled to the controller, the memory device including the control input in the form of a preloaded control sequence.   The control system of claim 1, wherein the frequency of the control signal is selected such that sufficient time for an insect muscle response is allocated before a subsequent control signal.   The control system according to claim 1, wherein the control signal includes a pulse train in which a positive potential and a negative potential applied to the flying muscles facing the insect are alternated.   2. The control system according to claim 1, wherein the control signal includes a pulse train in which a positive potential and a negative potential applied to an opposing visual lobe of the insect alternate.