UF ushers in a new age of engineering with a novel technology for 3-D printing the softest objects
By Cindy Spence

A dozen or so polymer jellyfish float in an aquarium in Tommy Angelini’s engineering lab, not alive but freaks of nature nonetheless, about to rock the world.

Just months ago, these jellyfish could not have existed; there was no way to make something so soft. That changed in 2014. Angelini was exploring ways to create fragile arrays of cells when he realized the contraption he had cobbled together not only did what he wanted it to do, but much, much, much more.

As experiments piled up — let’s try this, what if we try that — the contraption met every challenge, and doors long closed to scientific inquiry sprang open.

A new age of engineering, the Age of Soft Matter, had arrived.

As Angelini worked, he updated colleague and mentor Greg Sawyer on the eerily soft objects coming out of his lab. Sawyer issued a challenge.

“As engineers, you look at a jellyfish, and you say, that’s utterly impossible, how on earth could we manufacture that thing,” says Sawyer. “You want to make something? Make a jellyfish.”

Angelini did, and Sawyer says, “Now, let’s cross that off the impossible list, and get started.”

As a symbol of a new age and an engineering revolution that will change medicine and manufacturing, the no-longer-impossible jellyfish is perfect. If you can make a jellyfish, think what else you can make: cells, tissues, organs, tumors.


Before the jellyfish, there was a grant. Angelini had won a National Science Foundation Early Career Development Award, NSF’s most prestigious award for promising junior faculty, with a proposal to use the $500,000 to explore cell mechanics. To do that, he needed arrays of cells not confined to a petri dish. He needed cells in three dimensions.

“I wanted to study the basic physics of collective cell behavior,” Angelini says. “What do cells do spontaneously when driven by their own internal machinery?”

Tommy Angelini uses his lab’s refrigerator for quick calculations.

Angelini hired doctoral student Tapomoy Bhattacharjee and drew on assistance that ranged from a high school student working on a science fair project to Sawyer, a world-renowned tribologist and the Ebaugh professor in the Department of Mechanical and Aerospace Engineering. Angelini bought a see-through laminar cabinet commonly used by geneticists because it had a way to filter air. He procured a fine-tipped nozzle like those used in 3-D printers. All he needed was a way to hold the printed cells in place; in other words, something that did not exist.

In traditional 3-D printing, the nozzle deposits liquid on a platform, and it hardens layer by layer until an object takes shape. That method would not work with something as squishy as a cell, which could not harden and would not be supported in air.

Angelini needed a specialized material, one soft enough to allow the most fragile object to take shape, but strong enough to hold it in place, so it could be studied and manipulated. The substance had to be neutral, neither contaminating nor augmenting the object it cradled, and it had to be soluble so it would rinse off, leaving no trace. It was a tall order, but Angelini figured a granular gel medium might work.

You know it as hand sanitizer.

The granular gel medium is the same as hand sanitizer without fragrance or alcohol. It straddles the solid-fluid states that Angelini needed to both hold a fragile object and later release it because the substance is 99.8 percent water. The other 0.2 percent is a polymer. As the nozzle passes through, the gel heals in its wake, leaving no sign of disturbance other than the soft, printed object, visible through the clear gel.

The intended goal — studying cells in 3-D — had an unintended, but groundbreaking, consequence — the invention of 3-D printing of soft matter.

As word spread across campus, the kneejerk reaction was, “No, that isn’t possible.” As chemists, biologists, neurologists, doctors and engineers trooped through Angelini’s laboratory, Bhattacharjee demonstrated, printing jellyfish after jellyfish, filling an aquarium with polymer creatures.

“We showed them, ‘This is the science, this is how it works,’” Bhattacharjee says. “It’s fun for a physicist, it’s fun for a biologist.”

Disbelief, Sawyer says, quickly turned to, “Wow, this is really cool!” Seconds later, wheels turning, that became, “What can I do with it?”

Sawyer and Angelini had suggestions.


In 2015, the American Cancer Society estimates 1,658,370 cases of cancer will be diagnosed in the United States; 589,430 cancer patients will die. By 2020, treating cancer will cost the U.S. over $200 billion a year.

Perhaps more staggering than the statistics is cancer’s reach. Every family has a cancer story, and that makes cancer a grand challenge for medicine.

Greg Sawyer examines a small-scale, soft matter model of a brain.

For Sawyer, it’s a personal challenge as well.

In 2013, Sawyer was diagnosed with stage IV metastatic melanoma. At first he felt helpless but, being an engineer, he did his homework. He joined a new immune therapy clinical trial, had a trio of painful operations and months of intense radiation to fight the disease. When Angelini printed the jellyfish a year later, the intersection with cancer was clear.

When the College of Medicine’s Celebration of Research rolled around, they browsed the posters at the O’Connell Center to see if they could find a collaborator. They ran into cancer researcher Steve Ghivizzani.

“I listened to them talk about this new technology, and I thought, ‘That’s just crazy.’ Greg says, ‘Just think about it: If you had the ability to position cellular things in space without restrictions, what could you use it for?’”

Ghivizzani did think about it and emailed Sawyer that night. He was in.

Cancer has been a thorny research subject because it is a chameleon. A cancer cell in one person doesn’t behave like a cancer cell in another, even if the cancers are the same. Even more confounding, each tumor is heterogeneous. On its exterior, it might be gorging on nutrients and replicating rapidly. Deep inside, it may be almost starving, but still alive, waiting for nutrients before growing. With thousands of cancer cells in each tumor, figuring out how the cells interact will be a key to future cancer treatment.

Ghivizzani says a tool that could allow cancer research to take not one step, but possibly many giant steps, got him excited.

“Innovations in science can sometimes be subtle,” Ghivizzani says. “This rocks.”

Cancer researchers have been stuck for years with two models, the petri dish and the mouse.

Cancer cells are easy to grow in a petri dish. But the biology of a cell growing in a dish is different from the biology of a cell growing in a body. In the body, cancer cells compete with other cells for nutrients, exhibiting aggression, or malignancy. In a petri dish, without competition, they adapt to their environment and often lose the malignancy a researcher wants to study. Ghivizzani says about two-thirds of the genes expressed in a tumor in the body are expressed in opposite ways in a petri dish.

The other model is the mouse, but that, too, has limits. Many cancers don’t grow in mice, prostate cancer, for instance. Most mice used for cancer research also have been genetically engineered to suppress their immune system, so immune therapies cannot be studied. Cancer grows slowly in mice, if at all, and sometimes the patients succumb before the mice can be tested. To see inside the mouse, you have to sacrifice the animal and further study of the tumor.

What is needed is a three-dimensional model between a petri dish and a mouse: 3-D soft matter printing of cancer cells.

The goal is to harvest a patient’s cancer cells, print them into the granular gel, and allow them to grow. In theory, unlimited samples could be grown and an unlimited number of therapies tried. Researchers couldn’t use 10,000 mice at once, but they could grow 10,000 samples and try different approaches. From immune therapies to various drugs, all the tests could take place at once, saving critical time for the patient.

“We can use this system to learn a lot more a lot faster than we have been able to do,” Ghivizzani says. “Can you take each patient, print replicas of their tumor and then try different therapies? That’s where we want to go.”

Ghivizzani says the ability to collaborate with engineers on cancer research is key to reaching that goal. Working with Sawyer and Angelini one afternoon during a test, it looked like they would not be able to print fast enough to continue working the next day.

“Greg sat down and did the math, and they built another machine. By the next morning, they had it reconfigured to work the way we needed it to function,” Ghivizzani says. “Their ability to solve those kinds of technical problems that are not biologic . . . without that, we won’t get where we want to go.”

Sawyer, who feels the urgency of his fellow cancer patients every 100 days when he visits his doctors, says engineers are perfect partners for cancer research. By January, he says, UF engineers will equip a lab at the College of Medicine with engineering tools for new research.

“At first, cancer seemed far from engineering. But look at it; it’s a dynamic system, far from equilibrium, and maybe that’s not so strange to engineers. This is tumor engineering. Give us six months, and we can really help from an engineering standpoint.

“Ten years from now, I think this will be the way researchers work with patients’ cancers,” Sawyer says.


A new age of engineering creates a lot of work, and Sawyer and Angelini were eager to share the cool, new science. Department Chair David Hahn agreed to a Soft Matter Engineering Research Group, and the scientists who witnessed the first jellyfish demonstrations signed on. Today, there are 28 collaborators, including two Sawyer protégés at the University of Illinois Urbana-Champaign and Florida International University.

“Tommy made that breakthrough, printing in the granular gel, that was the quantum step forward,” Hahn says. “Now there’s a thousand things to do on top of that with the subtleties of the materials, applications, the science behind it, understanding how these materials function. It’s huge.”

Teams of engineers and doctors will tackle four areas: mechanics and failure theories of soft matter; soft matter manufacturing; transport of materials through soft matter; and soft matter for medicine.

The objects printed in the lab are orders of magnitude softer than any man-made object. Angelini says he doesn’t know of a lower limit to the mechanical integrity of the objects the lab can make, and Hahn says new mechanics and failure theories will be needed; what works for titanium will not work for cells and polymers a million times softer.

“In simple terms, a hundred-plus years that we’ve built a foundation on in traditional mechanics is largely off the table with soft matter,” Hahn says. “It really is a whole new frontier of engineering.”

Floating jellyfish

Angelini’s lab did informal tests. One early jellyfish was placed in a jar and examined weekly. It held up just fine until, at the seven-month mark, it was knocked off a shelf. On impulse, Angelini tossed a container of polymer jellyfish in his backpack to travel to a conference in Germany. They survived, so he sent them by FedEx to a colleague in Cleveland and had them shipped back. The jellyfish were no worse for wear.

Now it’s time for science to back up — or disprove — the anecdotes.

Sawyer, the go-to guy for expertise on friction and wear in mechanics and materials, says what engineering has lacked from the Stone Age to the Plastics Age and beyond is softness; soft materials have always confounded engineers.

“What is soft matter? Actually, it’s everything; it’s most of the human body. The hard matter is the weird stuff. We’ve worked with it since the Stone Age because we knew the rules,” Sawyer says. “Now, we’ve entered the Soft Matter Age.”

Engineering Professor Kevin Jones, who views materials science through a broad lens that includes anthropology, the classics, humanities and history, is creating a soft matter module for an interdisciplinary course he coordinates, “The Impact of Materials on Society.” When he wrote the course flyer, one of the teasers was, “What future materials innovations will revolutionize your world?”

“I didn’t realize that at that very moment, one of those revolutions was taking place across campus,” Jones says.

That there is no textbook for this field that didn’t exist six months ago is an opportunity, not a problem, Jones and Hahn agree.

“This has a huge wow factor. Students who thought of engineering as cars and gears, can see that mechanical engineering can be about tissue scaffolds and artificial organs and other cool stuff,” Hahn says. “The jellyfish, it’s a vehicle for excitement.”


No one is waiting for theories. Across campus, scientists are making soft materials at such a pace that six patents are pending on a technology not yet a year old.

“We had no way to make materials so soft in the past and no reason to study it. Why study something so soft and gooey you couldn’t use it for anything?” Jones says. “The minute you can engineer something out of it, that changes everything.”

The lead in manufacturing is Curtis Taylor, assistant professor of mechanical and aerospace engineering. Already, Taylor is close to solving one of the first questions raised by the new technology: Is it possible to print efficiently with more than one material? Early experiments involved printing with a single material, in most cases polymers or cells. What if you wanted to print an object with different textures at different layers — a phantom brain, for instance, with a tumor under the surface?

Taylor and a team of students tackled that problem. They came up with an acrylic tube with four ports, one for the granular gel medium and three for other materials. To avoid the need for a valve to shut off one port so another can open, they came up with an ingenious solution: use the granular gel, which easily transitions from fluid to solid, as a plug.

The device is the size of a piece of bubblegum and would cost just $2. To make cellular or sterile materials implanted in humans the device is disposable, and although the prototype is acrylic, biodegradable materials work, too. As a manufacturing innovation, it looks simple, but it’s a workhorse.

“This little device replaces four nozzles, four pumps, four different needles, four different mechanisms for putting the needles into the gel,” Taylor says.

Also in the works are larger machines for larger objects and automation with robotic arms that can build from any angle. Questions remain, including the sequence of printing — inside out or outside in — and how fast it is possible to print with precision. To answer them, Taylor is actively recruiting. “I need a student,” he says, “I need a band of students.”

The printed soft materials can mimic the softness of human body parts, like the brain, and that opens new avenues for medical education, says neurosurgery professor Frank Bova.

A prototype of a hollow, flexible tube that represents on-demand, patient-specific medical devices.

By manufacturing artificial brains and other phantom organs that students can practice on, medical education could take a leap forward, Bova says. Models of bones and cartilage have been readily available for practice, but not soft organs.

One problem with teaching medical students is having the right case at the right time. Often, complicated cases come in when a student is learning more basic methods. Bova envisions a library of phantoms, easily printed as needed, giving students cases appropriate for their skill level as their skills grow.

Other phantoms could benefit personalized medicine. A patient’s brain could be scanned and printed with its own personal architecture — tumors, blood vessels, neurons — allowing the surgeon to rehearse before operating on the patient.

Angelini says, “Can you imagine, hearing your surgeon say, ‘Good morning, I’ve practiced this surgery on your brain five times already. You’re in good hands.”

Some colleagues are stunned by the simplicity of his idea and how easily it adapts to different uses. But that’s engineering, Angelini says, the best solutions are simple and elegant.

“Every time we thought of a new thing to do with this technology, it turned out to be really amazing. Every time we thought of a new task or a new test, the material we were using turned out to have a fantastic solution,” Angelini says.

The jellyfish — the impossible jellyfish — was almost too easy, but the road ahead holds challenges.

“I think we will help people,” Sawyer says. “This may not help me, but it will help somebody.

“We’re engineers, and engineers, regardless of what it is, feel there’s got to be something we can do to effect change. There’s a certain amount of pleasure you get from just being in the fight. I like that.”

Related Website:

This article was originally featured in the Fall 2015 issue of Explore Magazine.


黄色直播软件 牛牛视频app 千层浪 盘他直播app 内裤直播app 小奶狗app 探探直播app JOJO直播 千层浪app 富二代短视频app 彩云直播app 铁牛 health2 富二代f2 夜夜直播 月亮直播app 杏趣直播 夜狼直播app 成版人音色短视频app 千层浪直播app 成版人短视频app 美梦视频 杏吧直播app 米老鼠直播 swag台湾app 夜魅直播app 水果视频 老王视频app 麻豆传媒直播app 烟花巷直播app 小花螺直播 东京视频app 夜夜直播app 富二代短视频app 最污直播app 豆奶app 灭火卫视 JOJO直播下载app视频免费最新 木瓜下载app视频免费最新 月光直播 花姿app 盘她直播 丝瓜app 草莓直播app MM直播app 西瓜直播app 91直播 草榴直播app 小天仙直播下载app视频免费最新 四虎app 成人直播 年华直播app 小蝌蚪视频app health2 冈本视频 小狐仙视频 午夜直播 樱花雨直播 富二代f2抖音下载app视频免费最新 探探直播 花仙子直播app 探花直播 黄瓜视频 丝瓜视频 月色直播 泡芙短视频 樱花视频 花秀神器app ML聚合直播app 富二代f2短视频app 夜狼直播 A头条app 富二代短视频 咪哒app 樱花雨直播app 小天仙直播下载app视频免费最新 橙子直播app 梦幻直播app 年轻人片app 水晶直播 芭乐视频app lutube 大秀直播app 荔枝视频app 红楼直播app 最污直播下载app视频免费最新 橘子直播 Kitty直播 蓝精灵直播 暖暖直播 Kitty直播app 雨云直播app 和欢视频app 小v视频 香草视频app 香蕉视频 千层浪直播app 夜遇直播号 猛虎直播app 一对一直播 豆奶视频app 樱花app 杏吧直播app 金屋藏娇直播间app f2富二代app 7秒鱼 冈本 茄子视频app 粉色视频 iAVBOBOapp 雨云直播 微啪app 柚子直播app 蓝精灵直播app 成人直播app 可乐视频 蜜柚直播app 丝瓜视频污app IAVBOBOapp 花心视频app 酷咪直播 云上花直播下载app视频免费最新 妖妖直播 遇见直播 宅男之家 小公主直播 s8视频 秀儿直播 烟花巷直播 夜猫视频app 小宝贝直播 s8视频 花姿app 荔枝 千层浪app 香草视频app 恋夜秀场app 芭乐视频app 富二代f2抖音 小花螺直播app BB直播app MM直播app 橘子直播 豆奶短视频app 福利直播 盘她直播 福利直播 西瓜直播 咪哒直播app 小草莓 avgo下载app视频免费最新 污软件 荔枝 烟花巷 蝶恋花直播 杏吧直播app 97豆奶视频 樱花 探探直播app 猛虎直播app IAVBOBO下载app视频免费最新 月光直播 小怪兽 含羞草app 七秒鱼下载app视频免费最新 成版人茄子视频app 蝶恋花直播 享爱直播 蜜橙视频app 快猫短视频下载app视频免费最新 微啪app 向日葵app 豆奶抖音短视频app 盘她app 花友直播app 烟花直播 红颜app Avnightapp 冈本视频 小狐仙 97豆奶视频下载app视频免费最新 水仙直播 小优app 彩云直播app 香草视频app 暖暖直播app s8视频app 7秒鱼下载app视频免费最新 小草莓app 香蕉 夜魅直播 花心视频 iavboboapp 黄瓜app 梦幻直播 云雨直播 葫芦娃 烟花巷app 美梦视频app 水果视频 左手视频下载app视频免费最新 杏吧直播 橘子直播 榴莲视频 云上花 抖阴 avgo下载app视频免费最新 avgo下载app视频免费最新 丝瓜视频污app 蜜柚直播 探花直播 木瓜视频app 含羞草 黄瓜 七秒鱼直播 七秒鱼直播app 榴莲视频 佳丽直播 享爱 大番号 黄色直播软件 鸭脖视频app 恋人直播app 草榴视频app 向日葵视频app 千层浪直播app 烟花巷 快猫视频app 茄子视频 91视频 冈本视频app 木瓜视频 茄子 水蜜桃 小宝贝直播app 爱爱视频app 向日葵视频 盘她s直播 梦幻直播app 牛牛视频app 成版人茄子视频app 后宫app 小仙女 蝴蝶直播 奶茶视频app 后宫 七秒鱼直播app 玉米视频 大秀直播 左手视频 向日葵视频 蜜柚 久草视频 花姬直播 小奶狗 成人直播app 泡芙视频 冈本app 花心直播app 花心社区app 尤蜜app 芭乐app 陌秀直播 仙人掌app 朵朵直播 秋葵视频 樱花视频 梦鹿直播app 麻豆传媒直播 久草视频app 色秀直播 硬汉视频下载app视频免费最新 health2app 彩云直播app 桃花app 恋人直播app 米老鼠直播 黄瓜视频 奶茶视频 皮卡丘直播app 蝴蝶直播app 夜猫视频 米老鼠直播app 考拉直播app 香草视频app 七秒鱼 麻豆传媒 午夜直播间 水果视频 葫芦娃视频app 小公主直播app 花友直播 望月 蓝精灵直播app 大番号app AVBOBO下载app视频免费最新 iavbobo下载app视频免费最新 快狐短视频app 盘他直播 草莓直播app 七秒鱼直播 春水堂 月夜直播 BB直播app 向日葵视频 Avnightapp ML聚合直播 橘子直播 成人直播app 本色视频app 本色视频app 棉花糖直播app 成版人抖音富二代 卡哇伊直播app 97豆奶视频app 夏娃直播app 和欢视频 咪咪直播 望月直播 快猫短视频 蜜柚app 鲍鱼视频app Avnight 小仙女 ML聚合下载app视频免费最新 尤蜜下载app视频免费最新 灭火卫视 成版人音色短视频app 水晶直播app 夜遇直播号app 69热 奶茶视频 Kitty直播 91直播下载app视频免费最新 香草成视频人 依恋直播app 秀儿直播app 牛牛视频app 富二代app 盘她s直播app 小姐姐直播app 红高粱直播app 茶馆视频app 夜猫视频app 茄子视频 大小姐直播app 合欢视频app 泡芙视频 茶馆视频app 樱花app 水晶直播 豆奶视频app 樱花直播 小米粒直播app 黄瓜视频人 91视频app 主播福利app 香蜜直播app 黄鱼视频app Huluwa 铁牛app 盘她直播 浪浪视频 香蜜直播 午夜神器 花心视频 蘑菇视频app 成版人抖音app 花仙子直播app 云上花直播下载app视频免费最新 橘子直播app 浪浪视频app 盘她app 恋人直播 成版人抖音富二代 朵朵直播app 光棍影院 草莓app 尤蜜 花秀神器 iavbobo 小仙女 内裤直播app avgo下载app视频免费最新 含羞草app 杏花直播下载app视频免费最新 趣播app 榴莲视频 盘她 富二代短视频app 香蕉 猛虎视频app 幸福宝下载app视频免费最新 享爱直播 免费黃色直播 宅男之家app 灭火卫视 花狐狸直播 仙人掌app 香草视频 夜狼直播 彩云直播app 97豆奶视频app 四虎 花仙子直播下载app视频免费最新 swag视频app 91直播下载app视频免费最新 千层浪视频 媚妹秀app 可乐视频 秀色直播app 小草莓 快狐 么么直播app 米老鼠直播app 夜猫视频 小奶狗app 云上花直播 草榴短视频app 柚子直播app 花心社区app AVBOBO 月亮视频 小怪兽直播app 梦露直播 杏花直播app 茄子直播下载app视频免费最新 香蜜直播app 快狐app 猛虎视频 花心app 梦幻直播下载app视频免费最新 彩云直播app bobo直播 蓝精灵直播app 可乐视频app 小蝌蚪视频app 花心直播 91香蕉视频app 抖阴视频 红杏视频 欢喜视频 d2天堂 含羞草 午夜神器app 芭乐视频app 繁花直播 直播盒子 f2富二代 污直播 ML聚合 富二代f2抖音app 橙子视频app 冈本 蝶恋花直播 蜜蜂视频 小宝贝直播app Avnightapp 水晶直播app 灭火卫视 蝶恋花app 水蜜桃 本色视频app 桃花app 后宫app 心上人直播 Avnightapp 火爆社区app 橘子直播app Huluwa iavboboapp 铁牛 9uuapp 盘她app 蜜蜂视频 快狐短视频 月光直播app 富二代f2 小草视频 妖妖直播 米老鼠直播app 泡芙app 色秀直播app 桃花直播 水果视频app f2富二代app 草莓app 茄子直播 蜜橙视频 抖阴app 富二代f2短视频 东京视频 红杏视频 69视频 豌豆直播 草榴视频app 咪咪直播 7秒鱼app s8视频 九尾狐直播app 暗夜直播app 左手视频app 皮卡丘直播app 恋人直播app 丝瓜视频污 富二代f2抖音 夜魅直播app 鸭脖视频app 薰衣草直播 趣播 swag台湾app 樱桃视频app 秀儿直播下载app视频免费最新 7秒鱼直播app 花心视频app 爱爱视频app iavboboapp 香蜜直播 梦露直播app 杏趣直播 尤蜜app 比心直播 69热app 杏花直播 性福宝app 抖阴 樱桃视频app 快猫视频app 红玫瑰直播下载app视频免费最新 蝶恋花直播app 红颜 小可爱app 玉米视频 豌豆直播app 污直播app 金鱼直播 豆奶短视频app 富二代f2短视频app 七仙女直播app 97豆奶视频 小宝贝直播app 丝瓜视频污app 蓝精灵直播app 杏花直播下载app视频免费最新 笔芯直播 香草成视频人 快狐 污直播app 粉色视频 梦幻直播app 榴莲视频app 福利直播 好嗨哟直播下载app视频免费最新 快狐下载app视频免费最新 樱花雨直播下载app视频免费最新 月色直播 梦露直播app 恋夜秀场 葡萄视频app 盘他直播 蜜柚直播app 小宝贝直播app 樱桃视频 彩色直播 丝瓜草莓视频app 幸福宝app 花姿直播app 大小姐直播app 幸福宝下载app视频免费最新 69热app 猛虎直播app 快猫短视频 成版人短视频app 小米粒直播下载app视频免费最新 富二代f2app 花心视频app 梦幻直播app 蝶恋花 秀色直播app 小怪兽 iAVBOBO 小优app 葫芦娃视频app 97豆奶视频下载app视频免费最新 花心视频 享爱直播 蚪音 久草视频app 蜜柚 小狐仙视频app 梦鹿直播app 麻豆视频app 后宫视频app 花狐狸直播app 心上人直播app 秀儿直播 红楼直播app 草榴直播 柠檬视频app 探花直播 可乐视频app 奶茶视频 花心社区 合欢视频app 小怪兽直播app 七秒鱼直播app 香蜜直播 浪浪视频 大菠萝app 成版人快手app 黄色直播软件app 月光直播 好嗨哟直播 久草app 小姐姐直播app 恋夜秀场 斗艳直播 比心直播 金屋藏娇直播间 草榴视频 富二代app 草榴视频app