Scientists from the famed Massachusetts Institute of Technology have just published a research study in the journal Advanced Materials where they describe a new invention: a “living tattoo.”

It is a sort of temporary tattoo that is amazing because the ink is actually alive.  The good interesting about this is that the living ink can be programmed to be brighter depending on the environment, like a biological dimmer switch.

This sounds like it is purely for aesthetics, but there are many useful things that can be done with this new technology.

The research was carried out jointly by Professor Xuanhe Zhao and Professor Timothy Lu. What they and their graduate students have created is a thin layer, almost like a see-through sticker, with a picture of a multi-colored tree on it.

The sticker can then be put on the body. The tree is made of living ink, which has inside of it bacteria. This sounds gross, but these are actually good bacteria, that do not cause any harm whatsoever to the human body. They are in there because they have an interesting property.

The bacteria in the ink can respond to different stimuli. For example, if someone with this tattoo jumps in a pool, and the pH balance is off, a person without this “tattoo” might not be able to tell, but with it, one of the colorful branches of the tree would light up, signaling that the pH is not suitable for swimming.

The other branches of the tree might respond to temperature differences, which may act as a sort of thermometer for the wearer.

This technology has a long way to go, but this is a huge advancement. Previous attempts to make a living tattoo with living ink failed because different kinds of cells were used, rather than bacterial cells.

They found that those ruptured too easily and killed the ink. Soon, you might be getting these “tattoos” at your local mall.

Being a claustrophobic person, filming Batman was torture for Michael Keaton. The black rubber Batman costume triggered his claustrophobia every time he had to put it on, leading to panic attacks on set. He must have been the most relieved of the cast and crew when filming was finally done.

Movie icon, Al Pacino won an Oscar Award for his portrayal of Michael Corleone in The Godfather. This might not have been, as he almost left while shooting due to the fact that he perceived the atmosphere as hostile. He wanted to leave the movie in its entirety, but director Francis Ford Coppola convinced him to stay.

Fantastic Four is a movie franchise that has faced several controversies and behind-the-scenes drama over the year. The case of Jessica Alba in the 2007 Fantastic Four: Rise of the Silver Surfer is one that casts self-doubt over her acting skills. The director of the movie, Tim Story instructed Alba to cry in a way that her face still looked pretty. However, her crying looked too painful and real, something which Tim Story made clear to her. This incident made Alba doubt her abilities as an actor, and Story’s trust in her. Hopefully, these kinds of comments toward women don’t happen as much in current times.

The lead character in the Maze Runner trilogy faced some complications in the third and final installment of the movie series. This made him reconsider his future as an actor. While filming a scene for the movie in 2016, O’Brien had to be pulled off a moving vehicle in a stunt that led to serious injuries. The accident which delayed production till 2018, left O’Brien with a concussion, bone fractures as well as lacerations. It took a lot of strong will for O’Brien to put the accident behind him, and continue the filming of the movie, as well as take up other acting roles.

A vampire-centric film, Interview With The Vampire is a movie that legendary actor, Brad Pitt almost walked out on. Vampire movies are usually shot in dark venues or during nighttime, as vampires are burned by sunlight. This meant that Brad Pitt had to spend six months working in the dark in Pinewood Studios, wearing thick yellow contact lenses as well as an uncomfortable costume. Brad Pitt considered throwing in the towel, and it took the producer, David Geffen telling him that it would cost $40 million at that point, to convince him to stay.

Jeremy Renner is part of the Marvel Cinematic Universe taking the character of Hawkeye. After playing a bit-part role in the movie Thor, Hawkeye became a major character in The Avengers. Jeremy Renner however still had to act as a brainwashed version of his character, as Loki had control of his mind. Renner was not comfortable with this, and even requested that his character be killed.

Popular for her role as Hermione in the Harry Potter franchise, Emma Watson did not always enjoy being on the set of the Harry Potter series, as some scenes were difficult to shoot. She almost left on two occasions in particular; after shooting Order of the Phoenix due to educational constraints, and while shooting Deathly Hallows – Part 1 due to exposure to cold temperatures for extended periods.

Jim Carrey had a lot of work to do while filming How The Grinch Stole Christmas, as he spent close to nine hours every day in makeup and hair. The transformation covered him head-to-toe in a green fur and forced him to wear enlarged lenses. He was in so much pain and discomfort from the first day on set, that he told the director, Ron Howard he could not see it through. A former CIA specialist was then brought on set to help him act through the pain.

Robert Pattinson is popular for his role as Edward Cullen in the vampire movie series, Twilight. However, we might not have seen him in the Twilight series, as he considered quitting acting earlier. Acting as Salvador Dali in Little Ashes, he was not comfortable with the scenes in which he had to undress, as well as the one which required him pleasuring himself. He already decided to quit acting due to the discomfort that these scenes required, but the role of Edward Cullen was enough to change his mind.

Accidental Love is a movie that brought a lot of troubles on the production set. A production crippled with financial problems, several movie stars, as well as the crew, walked out during filming as they were not paid. James Cann is one of the actors that left the production of the movie early on, he claimed creative differences was his reason for leaving. This ‘difference’ referred to a scene where Cann was instructed to choke on a cookie while coughing at the same time, something he believed was impossible to achieve.

Before CGI came in vogue, hand-drawn animation was required to portray cartoon characters. As expected, it was not usually the perfect portrayal, which was why Lily Tomlin wanted to quit the movie 9 to 5. In several scenes of the movie, she was conversing with cartoon birds, and she was not impressed with what she saw of her performance to say the least. She offered to return all she had been paid to leave set, but she stayed after seeing an improvement.

The Misfits marked the end of an era, it saw the last appearances from Clark Garble and Marilyn Monroe. Shooting the movie was quite difficult, as it was shot in the heat of Nevada. Clark Garble was not impressed with the level of safety provided, as his stunt double got kicked in the face by a stallion, three different times. This caused him to walk off set, the director was however able to convince him to stay by highlighting the quality of the script. Clark Garble died before the movie was released.

Actors are usually at their best when the director shows full confidence in their skills. Daisy Ridley did not have the full confidence of J.J. Abrams on her first day on the set of Star Wars: The Force Awakens. He described her as “wooden”. This remark did not sit well with Ridley, it made her cry and hyperventilate. She considered quitting the movie as well.

Winona Ryder was involved in an incident at 12, after which she developed a phobia of drowning. It is therefore quite understandable that she required scuba training to film her underwater scene in Alien: Resurrection. While Winona Ryder did just fine, her co-star Ron Perlman nearly got drowned while filming. Needless to say, it must have brought back painful memories.

It is quite ironic that Daniel Franzese got bullied on the set of a movie, Bully. Daniel Franzese came out to say that Bijou Phillips verbally and physically abused him on the set of the movie. Bijou Phillips often made fun of Franzese’s orientation as well as his physical appearance. The bullying caused Franzese to walk off his set. They have since publicly reconciled, after Philips tendered a heartfelt apology.

The demands placed on Faye Dunaway by Roman Polanski, the director of Chinatown while filming made her snap. Roman Polanski wanting a top-class performance from Faye Dunaway mounted a lot of pressure on her even going as far as cutting off bathroom privileges. Faye Dunaway had to make do with a cup to relieve herself, and she ended up throwing this cup in his face in anger.

Jaimie Alexander suffered serious physical injuries while filming Thor: The Dark World, she fell down a flight of stairs during a stunt scene. The injuries she suffered include a chipped vertebrae, a herniated disk, as well as a dislocated shoulder. She underwent physical therapy afterward, recovering in time to finish filming.

Mary Elizabeth Mastrantonio and director James Cameron had a lot of altercations onset of The Abyss, as Cameron’s idea of perfectionism did not sit well with her. On the set of the movie, Mastrantonio was screamed at, slapped and even required CPR after nearly drowning. Mentally worn out from the trauma, Mastrantonio walked offset, but not before yelling “We are not animals!” at James Cameron. She eventually came back to set.

Mary Elizabeth Mastrantonio’s co-star in the movie The Abyss, Ed Harris also had issues with James Cameron. After filming a scene in which Ed Harris almost drowned, Cameron demanded that the scene be retaken as it was not good enough. This angered Harris who then allegedly punched Cameron before walking offset. Ed Harris like Mary Elizabeth Mastrantonio also came back.

The movie, Aeon Flux almost ended the acting career and mobility of Charlize Theron. While filming, she fell and injured her neck requiring a few months to stop in production. She later revealed the accident could have left more lasting effects as she was a mere centimeter away from being paralyzed. Thankfully, she recovered fully from the injury and completed filming.

One would expect that a former WWE star and a big guy like John Cena would be fearless. The filming of the 2009 movie, 12 Rounds, however, revealed that John Cena is scared of heights. In a scene that required rappelling down a skyscraper and dangling from a rope, John Cena’s anxiety was brought to fore and he considered quitting. He revealed all of these in the DVD extras.

While shooting Kill Bill: Volume 1, director Quentin Tarantino was said to have encouraged Uma Thurman to carry out a stunt. This stunt saw her driving, crashing into palm trees, an incident which she described as “negligent to the point of criminality”. This incident has led to a lot of controversies in recent years, as Thurman demanded its footage be released.

In the 1963 movies The Birds, Tippi Hedren had to work with live birds as the prop birds on set were not working. These live birds had to be tied to Tippi Hedren, and one of them pecked her close to the eyes. This was painful leaving Hedren in tears, after which she walked off set, saying “I’m done” amidst tears. Hedren came back to set after a week off.

In a film directed by Stanley Kubrick, a perfectionist director, Shelley Duvall suffered a nervous breakdown. A particular bat scene in the movie was shot 127 times, and left Shelley Duvall’s hair falling out. Shelley Duvall revealed how demanding filming The Shining was, and admitted that she almost quit on a number of occasions.

Jim Carrey had a change of mind over his role in Kick-Ass 2. Originally, cast for the role of a mobster-turned-superhero, Jim Carrey was not ready to see it through, following successive mass shootings. This made the writers of the script change his character to that of a born-again Christian who did not use guns. Despite the change, Jim Carrey did not promote the movie due to the graphic violence on display.

Away from the actors who wanted to quit because of the stress and accidents, Mike Myers almost walked offset because of a song. In the movie Wayne’s World, Mike Myers and Dana Carvey gave a rendition of Queen’s Bohemian Rhapsody and there was a disagreement over the song choice. Although Carvey wanted a Guns N’ Roses song, Myers had his way after he threatened to leave if Bohemian Rhapsody wasn’t used.

Johnny Deep was very uncomfortable playing the role of the title character in the movie What’s Eating Gilbert Grape? He felt the character had a close resemblance to his personality. At the time of production, he had a drinking problem and was at loggerheads with the director over the incomplete screenplay they were working with, making production an unenjoyable experience. Depp repeatedly struggled with a scene in which Gilbert greatly disrespected his mother, and the actor called Darlene Cates to apologize after the scene was done.

Stanley Tucci delivered an Oscar-nominated performance of his role as George Harvey in the movie The Lovely Bones, but it was quite difficult seeing it through. His character committed the crimes of sexual assault and murder of a little girl, something he described as painful. The nature of the character unsettled him, but he pulled it together and delivered.

Perhaps, Zoe Saldana would not be the big movie star that she is today, as she really considered quitting acting during the filming of Pirates of the Caribbean: The Curse of the Black Pearl. Saldana played a bit-part role in the movie and this exposed her to the elitist nature of the industry. She claimed to have been disrespected and talked down on, making her consider leaving it all behind. She would go on to star in movies like Avatar and Star Trek.

Due to director David Fincher’s quest for perfection, Jake Gyllenhaal almost left the set of Zodiac. There were several takes for scenes, with one scene in particular requiring 90 takes. This made Jake Gyllenhaal question his interest in the project, and if he was willing to continue it. He stayed eventually and the movie was wrapped up.

Playing Maggie on the zombie drama Walking Dead, Lauren Cohen sure had to deal with a lot of blood and gore on set. An incident in the third season of the series however almost saw her walking off, as her character Maggie was supposed to perform a caesarian section on another character. She initially was not up for that level of gore, but she eventually came around.

Adam Sandler does not get a lot of love from movie critics, as his movies are usually rated lowly. Despite this, his movies always do very well commercially. During the production of his 2015 movie, Ridiculous 6, four Native American actors walked off the set after feeling racist stereotypes as well as an inaccurate representation of the history of Native Americans.

Confessions of a Teenage Drama Queen is one of the best teen movies of the early 2000s. Allison Pill who acted alongside Lindsey Lohan in the movie, was put off by a lot of things she experienced during the making of the movie. She even considered quitting acting all together as she could not stand the numerous last-minute script changes which were made.

For fourteen years straight, Milla Jovovich was the star of the Resident Evil franchise. It is therefore very interesting to learn that she almost left after the first Resident Evil movie. The reason for this was the fact that Rain, another character in the movie, was taking center stage while Jovovich’s Alice was more or less the sidekick. She discussed it with Paul Anderson, the director who convinced her to stay before convincing her to be his wife years later.

Playing the titular role in Marvel series Jessica Jones, has been quite demanding for Krysten Ritter. She has suffered a lot of injuries, even biting her tongue on one occasion. She described the experience as very painful. She did not cut through, so her tongue healed fast. There was also no damage to her face or speech, so production was not paused.

Roar ranks highly among movies with the most recorded injuries. The reason for this is not farfetched, as several untrained animals were used on the set of the movie. These animals include tigers, pumas, lions, as well as wild cougars. The 1981 movie, co-produced by Tippi Hedren, who is Melanie Griffith’s mother, left Griffith with a lot of injuries. After being attacked by an animal on set, she required plastic surgery and several stitches. Thankfully, she was not disfigured.

Cast as Apollo Creed, Carl Weathers almost quit working on Rocky IV after Dolph Lundgren (Ivan Drago) went overboard during a fight scene. While filming, Lundgren threw Weathers three feet into a corner, an action which was not exactly part of the script. This unsettled Carl Weathers and he wanted to leave the set altogether. It took the intervention of co-star Sylvester Stallone to convince him to stay.

Although Gene Hackman delivered an Academy Award-winning performance as Detective Jimmy “Popeye” Doyle in The French Connection, it was not exactly an easy ride. For one, he was not the first choice for the role and he found it difficult to channel the rage of his character. He eventually got it right, and produced a stellar performance.

Just like Michael Keaton above, Michelle Pfeiffer found it difficult to don her costume in a Batman movie. Cast as Catwoman in Batman Returns, Pfeiffer struggled in her skintight costume. She always had to be powdered down and helped into the costume before it was then vacuum-packed. This was not all of her worries, as she also had to wear claws which were always hooking things, and a mask which choked her.

Michelle Rodriguez is popular for her role as Letty in the Fast and Furious franchise, but she might not have been involved in the movie at all. Rodriguez did not find the idea of a love triangle that involved herself, Dominic (Vin Diesel) and Brian (Paul Walker) tantalizing. Basically, the idea of cheating on an alpha male like Dominic with a cute guy like Brian did not sit well with her, and she spoke out. In the end, she played the part.