Neuralink is a chip which inserted in motor cortex of brain, which is specifically called as Brain Machine Interface (BMI).  The chip contains long and thin wires called threads with electrodes and it also fitted correctly to in the piece of skull. The threads will detect neural signals and ultimately these transmitted by the link. It is used to communicate with machines and even control them. It helps to study and cure various medical problem [1]. Nuralink Idea Invented and Patent by Pedram  Moheseni and Randolph Nudo in 2015. After one year in 2016, Elon Musk founded an American company and bought the patent by July 2019 it had received 158 million Dollars. Neuralink brain chip is mixed of both bits of intelligence (Technology and Human) and achieves an interaction between human and artificial intelligence. It connects with BMI technology which is important in scientific and technology value. It is a revolutionary project that helps people suffering from diseases like paralysis, Parkinson's, disease, etc. [2] same as neuralink a company called synchron, backed by bill Gates and jeff Bezos, may become the first to commercialise a brain implant that lets people control touchscreen devices using brain signals. in addition, same as synchron  Brain gate is an implant system that is developed to assist the people who have limbs loss or lose their bodily functions like patients with spinal cord injury. It is a mind-to-movement system that permits a paralyzed person to regulate a computer using his thoughts [3]. By superlative from both  Neuralink is a device that will be surgically implanted in your brain, allowing you to connect with and even control machines. It will also aid in the study of brain electrical impulses and the development of treatments to various medical problems. With neuralink, an 8 mm-diameter chipset called the N1 chipset will be implanted in your skull, with numerous cables containing electrodes and insulation for the wires.

       
           
       
Figure no. 1. Neuralink N1 chip

History Of Neuralink-

Neuralink was founded by Elon Musk and a team of seven scientists and engineers, Neuralink was launched in 2016 and was first publicly reported in March 2017. Jared John Birchall, the wealth manager of Elon Musk was made the President, CFO and CEO OF Neuralink in 2018. By July 2019, the company had a received a funding of $158 million, of which $100 million was from musk himself [2].  As of 2020, the company was located in the Mission District of San Francisco where it shared its headquarters with Open AI, another company co- founded by Elon Musk [4]. in past just similar technology to neuralink called brain gate is facing   One of the issues with this technology is that CNPs are implanted directly into the brain tissue. This is a particularly dangerous process since brain tissue is very sensitive. All objects that are inserted into the brain which can damage the parenchyma, the key elements of an organ essential to its functioning. Blood vessels can be damaged and cause micro hemorrhaging during insertion. Neurons can also be ripped and destroyed are the drawbacks of brain gate. Nuralink is general symbiosis between man and a machine or the artificial intelligence.  Elon Musk in the launch event of the Neuralink told that the company aims to “understand and treat brainly disorders” along with “preserving and enhancing our brain” and “create a well aligned Figure 2: The Neuralink Logo. Elon Musk in an interview also talked about how the company will try to recreate “the Neural Lace”, a fictional method of transferring brain’s content to a machine and vice-versa [5].                                                    

Brain Gate –

Brain gate is an electrode chip that’s implemented in the cortex region of the brain . It is a system developed by cybernetics in 10 years of research, a biotech company in the year 2003 in connection with neuroscience department at Brown University. It helps to exchange the electrical signals between brain and the electrical gadgets. The principle behind this brain implant system is with normal brain functions, brain signals are been generated, but they can’t be sent to arms, hands or legs, these signals are understood and translated to cursor movements, which helps the individual to regulate the computer by human thoughts. Special software carries all the signaling processes.[6]

Brain gate disadvantages –

* Costly

* High risk surgery

* Not been wireless yet

* Difficulty in understanding and learning

* The newest technology is 20bits per minute

       
           
       
Figure no. 3. Brain gate technology

Neuralink –                                                             

It is the innovative project involves a multifaceted approach combining neurosurgery, a Brain-chip-interface, and a Brain reading device. Neuralink ‘s methodology is the thin hair-like structure called ‘threads’, that connect to the directly in neuron. These wires will be surgically placed inside the brain using a robot, whose wire is thinner than a strand of hair. However, because of its flexibility neuralink's technology is more challenging to implant than the Utah Array. To address this issue, the company has developed “a neurosurgery robot capable of inserting six threads (192 electrodes) every minute,” (automatically)? It resembles a hybrid between a microscope and a sewing machine in appearance. It also avoids blood arteries, possibly resulting in a reduced inflammatory response in the brain.

1 Brain machine interface-

Brain Machine Interfaces (BMIs) or Brain Computer Interfaces (BCI) collect, analyse , and interpret brain signals into commands that are communicated to output devices that perform the desired activities .  Normal neuromuscular output pathways are not used by Brain Computer Interfaces (BCI). The main goal of BCI is to replace or restore useful function to people disabled by neuromuscular disorders such as amyotrophic lateral sclerosis,cerebral palsy, stroke, or spinal cord injury .Brain Machine Interfaces (BMI) or Brain to Machine Interface(B2M) have the potential to assist people with a variety of clinical problems, such as impaired sensory and motor functions as well as connect us to any machine that can read our brain's inputs. For this, we need to have a high bandwidth rate. BMI wasn't initially popular with clinical disorders because of the limited number of channels available for signal transmission, but they now have the potential  to aid people with a wide range of clinical problems. Researchers have used no more than 256electrodes to demonstrate human neuro-prosthetic control of computer cursors, robotics limbs, and voice synthesizer Although these successes suggest that high-fidelity Information  transfer between brains and machines is possible, development of brain-machine interface has been critically limited by the inability to record from large numbers of neurons.[7]

 2 Structure of neuralink-

2.1Threads

Threats are the ultra-thin, flexible polymers, which will contain the electrodes and will transfer the signal to the transmitter. Increase production is made possible by wafer-level micro-fabrication Which patents the thin film device with 3072 electrodes connected in each wafer. Neuralink contains 48 or 96 threads in each area and each threat contains 32 separate electrodes. Mainly this method is used to stick very integrated chips to the axon part of the neuron which has a higher signal in this area. which is implanted by the surgical robot. Every thread ends with a 16 -50 um square loop to make threading the needle easier. Injecting this type of 1024 electrodes thread into the outside layer of the brain avoids any veins or arteries. These electrodes communicate with the brain cells which are connected to a Bluetooth link that goes straight outside of the computing device.[8]

2.2 Amplifier-The electrodes are built around the Neuralink custom application-specific integrated circuit (ASIM). Which consists of 256 individually programmable amplifiers on cheap analog to digital converters (ADC) and peripheral control circulatory for serializing the digitized output. These amplifiers play a critical role in accurately capturing and processing brain activity, enabling seamless communication between neurons and the device. By boosting weak electrical signals, the amplifiers ensure reliable data transmission, essential for decoding neural information with precision. Their design focuses on minimizing noise interference and maximizing signal fidelity, crucial for deciphering complex brain patterns. Ultimately, these amplifiers facilitate the seamless exchange of information between the brain and external devices, unlocking the potential for revolutionary advancements in neurotechnology.

As a result, our brain is made up of neurons that fire all the time in reaction to electrical messages received when we see, hear, move, talk, or think. Every time a neuron fire in response to these electrical signals, a little electromagnetic field is created. Neuralink will essentially tap into the brain's small electric field generated by sinus junctions. To detect  these action potential tiny threads with electrodes that are about one-tenth the cross section of a human hair or roughly the size of a neuron are developed and injected into the brain. Each thread will be inserted by a r robot to avoid bursting blood vessels or causing stress. The insertion needle is 24 microns in diameter, which is significantly smaller than the current state-of-the-art in deep brain stimulation The processor for making all of this work is called the n1 chip. The n1 chip amplifies, digitizes, analyses, and transfers analogue brain signals captured by the threads to a pod device behind the ear. The pod device is the only thing that will be upgraded, and the implants will remain in place until the pod is removed and everything goes down. The n1 chip is a low-power 4 by 5millimetre chip with built-in technology for processing brain data. It can read 20,000 brain samples per second, indicating that these are true raw signals from a neuralink attached to a brain. Because the neural link comprises thousands of electrodes, it produces a cleaner, more dependable signal for more complicated application. The neural link's first application will be to tap into the primary motor cortex, which is the part of the brain that sends signals down to the spinal cord and onto the muscles to drive movement. It will start with simple things like a mouse and keyboard, but it could also be used to read signals from all movement, including speech, and finally  it could be used to restore movement in  someone’s own body The materials or qualities that would cause the brain to not only accept but also believe that the neuralink is a part of it [9].

2.4 Robot -

The “Robot” is designed with a sole purpose of inserting the threads in least invasive manner. The Robot consists of seven parts-

a) Loaded needle pincher cartridge.

b) Low-force contact brain position sensor.

c) Light modules with multiple independent wavelengths.

d) Needle motor.

e) One of four cameras focused on the needle during insertion.

f) Camera with wide angle view of surgical field.

g) Stereoscopic3cameras.

2.5 DISCUSSION

The robot’s insertion head is mounted on a globally accurate,400 × 400 × 150 mm travel, 10 µm three-axis stage and holds a small, quick-swappable “needle-pincher” assembly .The needle is milled from 40 µm diameter tungsten-rhenium wire-stock electrochemically etched to 24 µm diameter along the inserted length the tip of the needle is designed both to hook onto insertion loops-for transporting and inserting individual threads-and to penetrate the meninges and brain tissue .The needle is driven by a linear motor, allowing variable insertion speeds and rapid retraction acceleration  (up to 30,000 mm/s2) to encourage separation of the probe from the needle.  The pincher is a 50 µm tungsten wire bent at the tip and driven both axially and rotationally It serves as a support for probes during transport and as a guide to ensure that threads are inserted along the needle path.

1. Animal Tests -

Since 2017, Neuralink has been testing the N1 chip by planting it in the brains of monkeys, pigs and other animals. From 2017 to 2020, Neuralink carried out these experiments in partnership with University of California, Davis (commonly known as UC DAVIS). Twenty-three monkeys were experimented on, out of which seven were transferred by the university to Neuralink at the end of their partnership. The initial success of these experiments was publicly confirmed in April 2021 when Elon Musk posted a video of a nine-year- old macaque monkey named Pager playing the video game Pong with its mind, with the help of the brain implant. They made this progress by compensating Pager with a banana smoothie at whatever point it finished a progression of undertakings in the game [10]. Then, at that point, the joysticks were detached, however Pager's psyche actually continued to convey similar messages to accept its prize i.e., the smoothie. These signs sent by the cerebrum permitted Pager to play the game through the mind chip, with next to no joysticks. In July 2023, Musk affirmed that these monkeys are currently fit for playing more perplexing computer games like Minecraft through their psyches. Experimentation has also been done on pigs. Electrodes were implanted in a pig”s spinal cord which allowed the engineers to control the movement of the pig?s limbs showing that the chip can be used to cure full body paralysis .Criticism and the Ethical Issues of these tests Neuralink?s experiments have been criticized many animal rights and safety organizations including the People for the Ethical Treatment of Animals which is more commonly referred to as PETA [11]. In 2022, the Physicians Committee for Responsible Medicine (PCRM) claimed that Neuralink and UC Davis had mistreated a number of monkeys, putting them through mental anguish, excruciating pain, and chronic infections as a result of surgery. PCRM believes that the fifteen monkeys which were not transferred to Neuralink were killed during the experimentation. In December 2022, Neuralink was reportedly the subject of a Agriculture (USDA) on possible breaches of Animal Welfare.[12] A report also states that the employees were rushed due to Elon Musk?s demands of fast reports which caused a lot of unnecessary harm and pain to these animals. Neuralink denied all these claims by stating that all the monkeys that passed away died after the experimentation was over, and not during the experimentation.

Initially, in 2022, the application for clinical human trials of the chip was rejected by The United States Food and Drug Administration (FDA) due to its incomplete information on the implant effect on the human body. However, in June 2023, The FDA approved clinical human trials. “The FDA acknowledges and understands that Neuralink has announced that its investigational device exemption for its implant/R1 robot was approved by the FDA and that it may now begin conducting human clinical trials for its device,” said an agency spokesperson.[13] On January 29, 2024, it was announced by Elon Musk that the implantation of neuralink into the human brain as a brain-computer interface will play a vital role in the advancement of neuroscience and neurobiology.  Musk said on space that the person on whom this first trial was made is reluctantly in a full recovery zone with no ill effects and is also able to move a mouse around the screen by just thinking. While the human implantation was done and recruitment was going on for a large sample clinical trial, the scientists discovered that this device has potential in the treatment of Parkinson disease.[14]

How Neuralink Symbiosis In Disease Curing-

Neuralink can play a crucial role in treating neurodegenerative disorder by the advanced mechanism of neuralink. it treats Parkinson’s, epilepsy, Alzheimer’s like diseases. Specifically, multielectrode neuro interfaces may become the basis for new communication systems and advanced assistive technologies for paralyzed people as well as control external devices and interact with the entire environment. eg- by integrating into new fast developed technologies, such as Smart Home and Internet of Things. Moreover, the brain-computer interface applications are very promising for detecting hidden information in the user’s brain, which cannot be revealed by conventional communication channels. Currently, the use of noninvasive brain-computer interfaces in these fields is limited by a low number of commands that can be recognized. This limitation arises from a relatively small number of commands that can be recognized. This limitation arises from a relatively small number of features, which can be extracted from the scalp-level electroencephalography or functional near-infrared spectroscopy recordings. The invasive brain-computer interfaces (or brain-machine interfaces) demonstrate much better performance than noninvasive brain-computer interfaces; however, they require a larger number of channels to obtain more detailed information about the individual spiking activity of the neurons across distributed cortical regions. The device reported in the paper of Elon Musk and Neuralink approaches the solution to this problem.

1 Epilepsy-

Epilepsy is neuronal disorder in which the brain is the center that controls and regulates all voluntary and involuntary responses in the body. It consists of nerve cells that normally communicate with each other through electrical activity. A seizure occurs when part(s) of the brain receives a burst of abnormal electrical signals that temporarily interrupts normal electrical brain function.

to predict epileptic seizures, the neuronal activity must be recorded from predefined focal areas of the brain, where an earlier manifestation of this pathological activity is mostly pronounced and can be promptly detected in real time. Recently, an efficient method for epilepsy prediction based on electrical brain activity was proposed. The method allows forecasting a focal seizure up to 5 seconds before it occurs. This time is sufficient for a brain-machine interface to generate a proper signal, which suppresses the forthcoming seizure. For drug-resistant patients, the complete abolishment of epileptic seizures might be achieved by a brain-machine interface/brain-computer interface that predicts a seizure onset, combined with a system that interferes with the process that causes the seizure. Thus, seizure prediction remains an unresolved problem due to insufficient information about neural processes in the onset brain area. Therefore, one possible and very important clinical application of the Neuralink technology is a brain-machine interface for patients with drug-resistant epilepsy. These brain-machine interfaces should imply the brain stimulation (electrical, magnetic, optogenetics, etc.) to interrupt or even prevent epileptic seizures. The stimulation can be delivered to the brain in either an open-loop or a closed-loop fashion. In the former case, there is no need to monitor the current brain activity, since the stimulation is activated manually or in accordance with a predefined stimulation protocol.

Although the open-loop systems enable a significant reduction in the number of epileptic seizures, it is obvious that a more efficient control of epileptic activity requires continuous monitoring of the current brain activity, which can be achieved by using closed-loop brain-machine interfaces. One of the first closed-loop brain-machine interfaces was the responsive neurostimulator designed by Neuropace Inc. (California, United States; Figure 10c). It contains implanted electrodes for recording the intracranial electroencephalography used by the algorithm, which determines the moment of time when a seizure starts. To interrupt the seizure, the triggered focal electrical stimulation is sent to a specific brain area.[16] It is important to point out that epileptic seizures are well detected using electro corticography or intracranial electroencephalography, which display a pronounced marker of the high-amplitude rhythmic activity. Recent studies reported a 100?curacy of this technique in detecting epileptic seizures in rats. Since the pre-ictal activity may not differ from a normal behavior, the prediction of seizures is a very challenging task. Although existing algorithms allow seizure predictions with high sensitivity, they are too complicated and too specific to be used in clinics. One of the closed-loop systems for the seizure prediction and prevention was recently tested in vivo in rats (Figure 11). The seizure prediction algorithm was based on the electrocorticography signals recorded by three electrodes in the cortex and the thalamus, as shown in Figure 11a. The brain-machine interface was able to correctly predict 45% seizures, but the number of false predictions varied from 20 to 100 per hour among animals. In this regard, one can expect that the technique developed by Elon Musk and Neuralink with thousands of channels will significantly improve seizure prediction. The large number of registered channels will increase classification accuracy in pre-epileptic state recognition and decrease the number of false positives during light slow wave sleep. This is indeed a step toward the next generation of brain-machine interfaces for drug-resistant epilepsy. The accurate seizure prediction algorithm based on the multichannel Neuralink technology enables the prevention of ongoing seizures and protects the patient against unnecessary stimulations caused by false alarms. Thanks to the developed brain-machine interface platform with thousands of channels, significant progress is expected in solving this important problem, enabling new clinical trials for patients resistant to drug therapy.[17]

2. Tinnitus -

 Tinnitus is a neurological disorder where ringing or buzzing in the ears in the absence of an external source is seen. It happens when the nerve that connects the inner ear with the brain, known as the vestibulocochlear nerve, is damaged due to extended loud noise, injury or deficiencies in blood supply. Elon Musk has claimed the Neuralink device could cure tinnitus by 2027. He states on X "Definitely. Might be less than 5 years away, as the current version Neuralinks are semi-generalized neural read/write devices with ~1000 electrodes and tinnitus probably need <<1000>

Future gen Neuralinks will increase electrode count by many orders of magnitude." These claims might appear impressive. Yet the underlying science is not feisty. In summary, the novel neurointerface by Elon Musk and Neurolink has all chances to become a real step forward to the next generation of brain-machine interfaces for both research and clinical applications. Invasive interfaces can help disabled people control external devices and communicate with other people. We believe that future communication technologies will be based on brain-computer interfaces that will read brain signals and translate them to messages, which then will be sent to mobile or other devices. Furthermore, invasive brain-machine interfaces will allow a direct communication between people by their thoughts.

Application Of Neuralink-

 In the process of developing neuralink N1, a handful of team members of this project took internet as their flat form to explain the process and applications of this brain machine interface and neuralink. The applications mainly consist of following

1. For Visual Orthitic

 As per report of neuralink team stated that this project has that ability to provide a visual prosthesis for people who have retinal al injury or myophia through eye injury. This idea is to eventually seal a cornea directly into the visual cortex and stimulating the signals to recognize the objects. Practically this happens by adjusting the frequency and wavelength firmly to the sensor to have a artificial eyesight.