Breaking News
December 18, 2018 - Artificial intelligence and the future of medicine
December 18, 2018 - Montana State doctoral student receives grant for her work to improve neuroscience tool
December 18, 2018 - Early postpartum initiation of opioids associated with persistent use
December 18, 2018 - Russian scientists identify molecular ‘switch’ that could be target for treatment of allergic asthma
December 18, 2018 - Surgeons make more mistakes in the operating room during stressful moments, shows study
December 18, 2018 - Immune cells explode themselves to inform about the danger of invading bacteria
December 18, 2018 - Malnutrition in children with Crohn’s disease linked with increased risk of surgical complications
December 18, 2018 - FDA Approves Motegrity (prucalopride) for Adults with Chronic Idiopathic Constipation (CIC)
December 18, 2018 - The long and short of CDK12
December 18, 2018 - CMR Surgical partners with Nicholson Center to launch U.S.-based training program for Versius
December 18, 2018 - Findings reinforce guidelines for cautious use of antipsychotics in younger populations
December 18, 2018 - Study finds new strains of hepatitis C virus in sub-Saharan Africa
December 18, 2018 - New battery-free, implantable device aids weight loss
December 18, 2018 - Parental alcohol use disorder associated with offspring marital outcomes
December 18, 2018 - Novel Breast Imaging Technique Might Cut Unnecessary Biopsies
December 18, 2018 - What can a snowflake teach us about how cancer spreads in the body?
December 18, 2018 - Management of nausea and vomiting in pregnancy costs the NHS more than previously thought
December 18, 2018 - Green leafy vegetables may reduce risk of developing liver steatosis
December 18, 2018 - Veganism linked to nutrient deficiencies and malnutrition if not planned correctly
December 18, 2018 - Coming Soon: A Tiny Robot You Swallow to Help You Stay Healthy
December 18, 2018 - Modified malaria drug proven effective at inhibiting Ebola
December 18, 2018 - Study finds epigenetic differences in the brains of individuals with schizophrenia
December 18, 2018 - Fitness instructors’ motivational comments influence women’s body satisfaction
December 18, 2018 - Study focuses on modification of lipid nanoparticles for successful brain cell targeting
December 18, 2018 - New gut bacteria may be effective against obesity, metabolic and mental disorders
December 18, 2018 - New two-in-one powder aerosol to upgrade fight against deadly superbugs in lungs
December 18, 2018 - Biofilms feed with swirling flows
December 17, 2018 - Study identifies specific neurological changes related to traumatic brain injury
December 17, 2018 - New study confirms geographic bias in lung allocation for transplant
December 17, 2018 - Research focuses on optimization of solid lipid nanoparticle that encapsulates Vinorelbine bitartrate
December 17, 2018 - Carpal tunnel syndrome – Genetics Home Reference
December 17, 2018 - A novel insulin accelerant
December 17, 2018 - Tips for caring for patients with disabilities, from a mother and physician
December 17, 2018 - Menopause-related sexual, urinary problems tied to worse quality of life
December 17, 2018 - In-school nutrition programs among students limit increases in BMI, finds study
December 17, 2018 - Risk for Hospitalization for Heart Failure Greater With Diabetes
December 17, 2018 - Food assistance may help older adults adhere to diabetes meds
December 17, 2018 - Supporting a family’s goals during a difficult pregnancy
December 17, 2018 - Neurons with Good Housekeeping Are Protected from Alzheimer’s
December 17, 2018 - New approach to tumor analysis could improve prognosis for bowel cancer patients
December 17, 2018 - New ‘epigenetics-based’ cervical cancer test outperforms Pap smear and HPV tests
December 17, 2018 - Ten year follow-up after negative colonoscopy related to reduced risk of colorectal cancer
December 17, 2018 - CTF along with NTAP and Sage announce first-ever open data portal for neurofibromatosis
December 17, 2018 - Intimacy: The Elusive Fountain of Youth?
December 17, 2018 - Will saliva translate to a real diagnostic tool?
December 17, 2018 - DFG establishes nine new Research Units and one new Clinical Research Unit
December 17, 2018 - Assisted living’s breakneck growth leaves patient safety behind
December 17, 2018 - America’s teens report dramatic increase in their use of vaping devices in just one year
December 17, 2018 - Enlarged heart linked to a higher risk of dementia
December 17, 2018 - Prostate cancer detection using MRI now first-line investigation tool
December 17, 2018 - Loughborough academics part of new project investigating effectiveness of personalized breast cancer screening
December 17, 2018 - Adolescents who use cognitive reappraisal had better metabolic measures, shows study
December 17, 2018 - Probiotics may offer therapeutic benefits for biopolar patients
December 17, 2018 - Stealth BioTherapeutics Granted Fast Track Designation for Elamipretide for the Treatment of Dry Age-Related Macular Degeneration with Geographic Atrophy
December 17, 2018 - Studies reveal role of red meat in gut bacteria, heart disease development
December 17, 2018 - Eisai enters into agreement with Eurofarma for its anti-obesity agent lorcaserin
December 17, 2018 - Researchers use brain connectome to reassess neuroimaging findings of Alzheimer’s disease
December 17, 2018 - “Miracle” baby survives Ebola in Congo and rapid a new Ebola detection device
December 17, 2018 - Mechanisms behind neonatal diabetes uncovered
December 17, 2018 - AHF urges the WHO to expedite approval process for vaccine effective against Ebola
December 17, 2018 - Study finds misuse of benzodiazepines to be highest among young adults
December 17, 2018 - TGen receives PayPal grant to underwrite costs of genetic tests for children with rare disorders
December 17, 2018 - New research highlights why HIV-infected patients suffer higher rates of cancer
December 17, 2018 - Antibiotic-resistant bacteria could soon be targeted with Alzheimer’s drug
December 17, 2018 - Rutgers scientists take an important step in making diseased hearts heal themselves
December 17, 2018 - Tailored Feedback at CRC Screen Improves Lifestyle Behaviors
December 17, 2018 - Loss of two genes drives a deadly form of colorectal cancer, reveals a potential treatment
December 17, 2018 - How the Mediterranean Diet Can Help Women’s Hearts
December 17, 2018 - Sustained connections associated with symptoms of autism
December 17, 2018 - Concussion rates among young football players were higher than previously reported
December 17, 2018 - Cresco Labs granted approval to operate marijuana dispensary in Ohio
December 17, 2018 - Study provides insight into health risks facing new mothers
December 17, 2018 - AMSBIO expands Wnt signaling pathway product range to aid research
December 16, 2018 - Surgical treatment unnecessary for many prostate cancer patients
December 16, 2018 - Excess weight responsible for cancers globally finds report
December 16, 2018 - Regular sex associated with greater enjoyment of life in seniors
December 16, 2018 - Social stigma contributes to poor mental health in the autistic community
December 16, 2018 - Multidisciplinary team successfully performs complex surgery on patient suffering from enlarged skull
December 16, 2018 - Experts analyze data that can guide antidepressant discontinuation
December 16, 2018 - Menlo Therapeutics’ Successful Phase 2 Clinical Trial of Serlopitant Demonstrates Reduction of Pruritus Associated with Psoriasis
New optical trapping and tweezing device for manipulating, moving tiny objects

New optical trapping and tweezing device for manipulating, moving tiny objects

image_pdfDownload PDFimage_print

When you shine a beam of light on your hand, you don’t feel much, except for a little bit of heat generated by the beam. When you shine that same light into a world that is measured on the nano- or micro scale, the light becomes a powerful manipulating tool that you can use to move objects around – trapped securely in the light.

Researchers from the Structured Light group from the School of Physics at the University of the Witwatersrand in Johannesburg, South Africa, have found a way to use the full beam of a laser light, to control and manipulate minute objects such as single cells in a human body, tiny particles in small volume chemistry, or working on future on-chip devices.

While the specific technique, called holographic optical trapping and tweezing, is not new, the Wits Researchers found a way to optimally use the full force of the light – including vector light that was previously unavailable for this application. This forms the first vector holographic trap.

“Previously holographic traps were limited to particular classes of light (scalar light), so it is very exciting that we can reveal a holistic device that covers all classes of light, including replicating all previous trapping devices,” Professor Andrew Forbes, team leader of the collaboration and Distinguished Professor in the School of Physics where he heads up the Wits Structured Light Laboratory.

“What we have done is that we have demonstrated the first vector holographic optical trapping and tweezing system. The device allows micrometer sized particles, such as biological cells, to be captured and manipulated only with light.”

The final device could trap multiple particles at once and move them around just with vector states of light. The experiments for this study were performed by Nkosi Bhebhe as part of his doctoral studies. The work is published in Nature’s on-line journal, Scientific Reports.

In conventional optical trapping and tweezing systems, light is focused very tightly into a small volume that contains small particles, such as biological cells. At this small scale (typically micro- or nanometres) the forces that the light can exert are significant, so particles can be trapped by the light and then controlled. As the light is moved, the particles will move with it. This idea won American scientist Arthur Ashkin the 2018 Nobel prize in Physics. Originally the light was controlled mechanically with stages and mirrors, but the idea was later improved on by moving the light around holographically, that is, by using computer generated holograms to control the light without moving parts, thereby controlling the particles. Until now only special classes of laser beams, called scalar beams, could be used in such holographic traps.

In their paper titled: A vector holographic optical trap the Wits researchers showed how to create and control any pattern of light holographically, and then used this to form a new optical trapping and tweezing device.

“In particular the device could work with both the traditional laser beams (scalar beams) as well as more complex vector beams. Vector beams are highly topical and have found many applications, but no vector holographic trap was possible until now,” says Forbes.

The Wits researchers demonstrate their new trap by holographically controlling both scalar and vector beams in the same device, advancing the state-of-the-art and introducing a new device to the community. The group expects the new device to be useful in controlled experiments in the micro- and nano-worlds, including single cell studies in biology and medicine, small volume chemical reactions, fundamental physics and for future on-chip devices.

Having previously shown that it is possible to create hundreds of custom light patterns from one hologram, the research brings together their prior work on holographic control of light with the application of optical trapping and tweezing.

How a holographic optical trap works

In a conventional optical trap, light is focused very tightly so that it can exert forces on matter. The matter, say a small particle, gets trapped in the light. When the light is moved by mirrors or mechanical stages, so the particle moves with it. This is referred to as optical trapping (capturing the particle) and optical tweezing, moving the particle as if with tweezers, but in this case tweezers made of light. To make the control less mechanical, researchers used holograms to control the light. With spatial light modulators one could encode structured light patterns and move those patterns around inside the trap, so that many particles could be trapped and moved simultaneously. This opened many new exciting fields, but the final holographic optical traps (HOTs) were limited to only scalar beams of light, a tiny fraction of what was possible. The other class of optical beams, vector states, were considered not possible to control holographically. With the new vector HOT, all states of light can now be used. Time will time what this means for the community at large.

Source:

http://www.wits.ac.za/news/latest-news/research-news/2018/2018-11/shedding-a-new-light-on-optical-trapping-and-tweezing.html

Tagged with:

About author

Related Articles