Search Search

2016 Cohort

Rob Hurt

Advisor: Mikhail Shapiro       

Option: Neurobiology


Lab Website:

Current Research: Achieving noninvasive control of neural circuit activity is a longstanding goal that until now has only been effectively addressed using electrical and magnetic modalities. However, most approaches that use these forms of energy suffer from limited penetration depth, spatiotemporal resolution, and cell-type specificity, and require expensive hardware to implement. A promising alternative modality is ultrasound, which can penetrate deep into the brain, can be focused at depth, and requires relatively simple and inexpensive hardware. Rob is currently exploring strategies to introduce cell-type specificity to this stimulation paradigm by using genetically encoded gas-filled protein nanostructures to amplify the effects of ultrasound stimulation on genetically-defined subpopulations of cells. This technique, termed “acoustogenetics,” could ultimately be used to deliver targeted neural stimulation to freely behaving large animals, either independently or in combination with other modalities such as MRI or photoacoustics. As an undergraduate, Rob studied the cellular and molecular mechanisms of fear memory storage and retrieval in a mouse model of auditory fear conditioning, and in the future he hopes to apply acoustogenetics to the study of learning and memory.

Selected Publications and Presentations:

  • Hurt RC, Garrett JC, Keifer OP, Jr., Linares A, Couling L, Speth RC, Ressler KJ, Marvar PJ. Angiotensin type 1a receptors on corticotropin-releasing factor neurons contribute to the expression of conditioned fear. Genes Brain Behav. 2015;14(7):526-533.
  • Keifer OP, Jr., Hurt RC, Gutman DA, Keilholz SD, Gourley SL, Ressler KJ. Voxel-based morphometry predicts shifts in dendritic spine density and morphology with auditory fear conditioning. Nature communications. 2015;6:7582.
  • Keifer OP, Jr., Hurt RC, Ressler KJ, Marvar PJ. The physiology of fear: reconceptualizing the role of the central amygdala in fear learning. Physiology. 2015;30(5):389-401.
  • Dobreva T, Brown D, Kumar S, Luo Y, Hurt R, Deverman BE, Gradinaru V. “Engineering novel adeno-associated viruses for enhanced transduction and target specificity across the CNS by adopting high-throughput in vivo and in silico methods.” Society for Neuroscience Annual Meeting, San Diego, CA. (November 2016).

Why Rob chose Caltech: "As a neuroscientist working in a chemical engineering lab, I’m very interested in doing interdisciplinary research. I thought that Caltech’s small size and its tight-knit community would give me the opportunity to learn from collaborators with vastly different backgrounds and skillsets, and so far that has turned out to be true."

In Rob's words: "I like the idea of being able to modify a system that’s not man-made, and that’s still a subject of intense study. It shows that you don’t have to completely understand how a system works in order to effectively engineer it, which is very encouraging to me as a biologist."


Zhewei Chen

Advisor: Niles Pierce

Option: Bioengineering

Linkedin: N/A

Lab Website:

Current Research: In the beginning, the earth was a boiling cauldron of nucleic acids, coiling and twisting in chaos. Through billions of years of evolution, these simple molecules eventually became us and the diversity of life around us. Although the earth has cooled down since then, the same DNA and RNA continue to twist and coil within us, in our cells. My graduate research seeks to understand the mysteries encoded in our DNA. DNA and RNA control the gene expression circuitry of our cells and make us who we are. Through nucleic acid folding simulations, rational design, and in vivo experimentation, I am trying to tease apart this complex gene circuitry and engineer novel genetic circuits which can detect nucleic acid sequences, arbitrarily link expression of unrelated genes, and enable precision editing and control of our genome. Prior to Caltech, I completed my undergraduate at the University of Michigan and worked for three years at Genentech Early Research in the field of cancer immunology.

Get to know Zhewei: “I enjoy exploring nature. Prior to starting graduate school, I went on a 2-week diving excursion with a friend to dive the walls near Apo island and Verde island in the Philippines. Thereafter, I traveled to Borneo to see orangutans, climbed Mt. Kinabalu, and test my climbing skills at Railay and Tonsai beach in Thailand. My most significant non-academic achievement thus far is climbing the snowy couloir of Mt. Whitney. Before graduation, I hope to climb Starlight and Thunderbolt peak in the North Palisades, Cerro Torre at the tip of South America, and the East Buttress of El Capitan.”

Zhewei chose Caltech because: “Situated beneath the sloping hills of the San Gabriel Mountains, Caltech is the heart land of dreamers, explorers, and aspiring scientists. For over a hundred years, our people have looked up into the stars, blasted astronauts into space, and scoured the far corners of the earth to find meaning and understand our place in the universe. For people who are in awe by nature, life, and the world around them, here is where our adventure begins.”


Ben Laccetti

Advisor: Julia Kornfield

Option: Chemical Engineering

Linkedin: N/A

Lab Website:

Current Research: In order to provide the eye’s main focusing power, corneal tissue maintains its curvature under stress from constantly oscillating intraocular pressure. If the shape of the cornea is compromised, vision can be severely impaired. Ben is developing a pneumatic device to gently embed drug particles in the cornea that are too small for the eye to feel or detect. By delivering eosin Y, a photosensitizing agent, it may be possible treat Keratoconus, a disease marked by corneal distension that is a leading cause of corneal blindness in the world today. Tight junctions in the corneal epithelium necessitate a new, gentle method of drug delivery, like the one Ben is currently developing. Ben completed a degree in chemical engineering with a concentration in bioprocess engineering from the Georgia Institute of Technology. He has also worked as a process engineer developing quality control and statistical process control at a manufacturing plant that produces syringes made to extend the shelf-life of protein-based therapeutics. He also has a bachelor’s degree in Mandarin Chinese from Emory University.

Get to know Ben: "Before falling in love with physics and engineering, I spent my days studying Chinese literature and history. In 2011, I was named one of Emory University's Language Students of the year. This was a culmination of a journey to learn the language that started when I was a 15 year old obsessed with Chinese cuisine. I received the award for my performance in the classroom and for my community outreach, which included developing an after-school Chinese Language course for 75 elementary and middle school students. I also managed a grant to build a traditional Chinese garden at an inner-city school and to teach the school's students about Chinese poetry and culture."

In Ben's words: "I am thrilled to be beginning my career in bioengineering during a time when drug treatments are transitioning from being administered globally in the body to direct, targeted administration. Molecular carrier assembly, receptor-ligand interaction, pH induced disassembly, biolistics... the tools of the "drug delivery" will make medical treatments safer and more effective. As a biophysicist and process engineer, I will be at the forefront of this field designing targeted drug delivery systems and finding ways to produce them in a cost effective manner."


Xinyan Liu

Advisor: David Tirrell

Option: Chemical Engineering


Lab Website:

Current Research: The frequent failure of antibiotic treatment might be related to bacterial persistence. Persister cells, as part of growing bacteria in a common laboratory bacterial culture, are known to be “immune” to antibiotics: they neither grow nor die in the presence of antibiotics. Xinyan is currently deploying bio-orthogonal non-canonical amino acid tagging (BONCAT) as a tool to study the bacterial phenotypic heterogeneity from isogenic populations and understand bacterial persistence. Results from his research will help understand how persister cells revert to a replicating form and reestablish active infection in clinical settings. Xinyan received Sino-Singapore Senior Middle 3 (SM3) scholarship and completed his undergraduate degree at National University of Singapore. He received Singapore-MIT Undergraduate Research Fellowship to perform summer undergraduate research and also received National Science Scholarship for his PhD studies. 

Selected Publications and Presentations:

  • Daniel E. Heath, Chee Ping Ng, Sharif Mohamed, Xinyan Liu, Paula T. Hammond, Linda G. Griffith, Mary B. Chan,  "Hydrogel microwell arrays for the isolation, culture, and analysis of rare cell populations",  Biomedical Engineering Society (BMES) Meeting,  Atlanta, GA, Oct-2012
  • Chee Ping Ng, Daniel E. Heath, Sharif Mohamed, Xinyan Liu, Mary B. Chan, Paula T. Hammond, Linda G. Griffith, "Novel microwell colony forming unit (CFU) assays for bone marrow stromal cells",  Biomedical Engineering Society (BMES) Meeting,  Atlanta, GA, Oct-2012

In Xinyan's words: "I love traveling. So far I have visited 25 countries. The growth rate of the number of countries I have visited is currently at one per year."

Get to know Xinyan: "I am a co-founder and director of a start-up company in Singapore. After I moved to Caltech, the company is now at “persistence” state: it neither grows nor dies due to limited time I could have."